Date Command Gives Wrong Week Number for Dec 31
up vote
19
down vote
favorite
When I try to get the week number for Dec 31, it returns 1. When I get the week number for Dec 30, I get 52 --- which is what I would expect. The day Monday is correct. This is on a RPI running Ubuntu.
$ date -d "2018-12-30T1:58:55" +"%V%a"
52Sun
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
Same issue without time string
$ date -d "2018-12-31" +"%V%a"
01Mon
linux command-line date
edited Nov 15 at 20:24
Jesse_b
11.4k23063
asked Nov 15 at 20:22
George Shafer
1104
add a comment |
up vote
19
down vote
favorite
When I try to get the week number for Dec 31, it returns 1. When I get the week number for Dec 30, I get 52 --- which is what I would expect. The day Monday is correct. This is on a RPI running Ubuntu.
$ date -d "2018-12-30T1:58:55" +"%V%a"
52Sun
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
Same issue without time string
$ date -d "2018-12-31" +"%V%a"
01Mon
linux command-line date
edited Nov 15 at 20:24
Jesse_b
11.4k23063
asked Nov 15 at 20:22
George Shafer
1104
9
"Date Command Gives Wrong Week Number for Dec 31" – "Wrong" according to which specification? Is the specification you are using the same one that the manual fordatesays it is using?
– Jörg W Mittag
Nov 15 at 22:41
2
Excel week number inconsistent results, Excel weeknum function returns wrong week, UI calendar shows wrong week number
– phuclv
Nov 16 at 6:27
2
You might be interested in Why does the MonthCalendar control show the wrong week numbers in Romania? The blog post is about Windows, but the issue being discussed is general (and seems to be the same as what you are encountering).
– a CVn
Nov 16 at 10:25
1
"The computer must be wrong, because I obviously didn't make a mistake!" reminds me of when I complained that the FORTRAN IV compiler must have a bug, because my first simple program couldn't have any errors...
– RonJohn
Nov 17 at 5:23
add a comment |
up vote
19
down vote
favorite
up vote
19
down vote
favorite
When I try to get the week number for Dec 31, it returns 1. When I get the week number for Dec 30, I get 52 --- which is what I would expect. The day Monday is correct. This is on a RPI running Ubuntu.
$ date -d "2018-12-30T1:58:55" +"%V%a"
52Sun
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
Same issue without time string
$ date -d "2018-12-31" +"%V%a"
01Mon
linux command-line date
edited Nov 15 at 20:24
Jesse_b
11.4k23063
asked Nov 15 at 20:22
George Shafer
1104
When I try to get the week number for Dec 31, it returns 1. When I get the week number for Dec 30, I get 52 --- which is what I would expect. The day Monday is correct. This is on a RPI running Ubuntu.
$ date -d "2018-12-30T1:58:55" +"%V%a"
52Sun
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
Same issue without time string
$ date -d "2018-12-31" +"%V%a"
01Mon
linux command-line date
linux command-line date
edited Nov 15 at 20:24
Jesse_b
11.4k23063
asked Nov 15 at 20:22
George Shafer
1104
edited Nov 15 at 20:24
Jesse_b
11.4k23063
asked Nov 15 at 20:22
George Shafer
1104
edited Nov 15 at 20:24
Jesse_b
11.4k23063
edited Nov 15 at 20:24
Jesse_b
11.4k23063
edited Nov 15 at 20:24
Jesse_b
11.4k23063
11.4k23063
asked Nov 15 at 20:22
George Shafer
1104
asked Nov 15 at 20:22
George Shafer
1104
asked Nov 15 at 20:22
George Shafer
1104
1104
9
"Date Command Gives Wrong Week Number for Dec 31" – "Wrong" according to which specification? Is the specification you are using the same one that the manual fordatesays it is using?
– Jörg W Mittag
Nov 15 at 22:41
2
Excel week number inconsistent results, Excel weeknum function returns wrong week, UI calendar shows wrong week number
– phuclv
Nov 16 at 6:27
2
You might be interested in Why does the MonthCalendar control show the wrong week numbers in Romania? The blog post is about Windows, but the issue being discussed is general (and seems to be the same as what you are encountering).
– a CVn
Nov 16 at 10:25
1
"The computer must be wrong, because I obviously didn't make a mistake!" reminds me of when I complained that the FORTRAN IV compiler must have a bug, because my first simple program couldn't have any errors...
– RonJohn
Nov 17 at 5:23
add a comment |
9
"Date Command Gives Wrong Week Number for Dec 31" – "Wrong" according to which specification? Is the specification you are using the same one that the manual fordatesays it is using?
– Jörg W Mittag
Nov 15 at 22:41
2
Excel week number inconsistent results, Excel weeknum function returns wrong week, UI calendar shows wrong week number
– phuclv
Nov 16 at 6:27
2
You might be interested in Why does the MonthCalendar control show the wrong week numbers in Romania? The blog post is about Windows, but the issue being discussed is general (and seems to be the same as what you are encountering).
– a CVn
Nov 16 at 10:25
1
"The computer must be wrong, because I obviously didn't make a mistake!" reminds me of when I complained that the FORTRAN IV compiler must have a bug, because my first simple program couldn't have any errors...
– RonJohn
Nov 17 at 5:23
9
9
"Date Command Gives Wrong Week Number for Dec 31" – "Wrong" according to which specification? Is the specification you are using the same one that the manual for
date says it is using?– Jörg W Mittag
Nov 15 at 22:41
"Date Command Gives Wrong Week Number for Dec 31" – "Wrong" according to which specification? Is the specification you are using the same one that the manual for
date says it is using?– Jörg W Mittag
Nov 15 at 22:41
2
2
Excel week number inconsistent results, Excel weeknum function returns wrong week, UI calendar shows wrong week number
– phuclv
Nov 16 at 6:27
Excel week number inconsistent results, Excel weeknum function returns wrong week, UI calendar shows wrong week number
– phuclv
Nov 16 at 6:27
2
2
You might be interested in Why does the MonthCalendar control show the wrong week numbers in Romania? The blog post is about Windows, but the issue being discussed is general (and seems to be the same as what you are encountering).
– a CVn
Nov 16 at 10:25
You might be interested in Why does the MonthCalendar control show the wrong week numbers in Romania? The blog post is about Windows, but the issue being discussed is general (and seems to be the same as what you are encountering).
– a CVn
Nov 16 at 10:25
1
1
"The computer must be wrong, because I obviously didn't make a mistake!" reminds me of when I complained that the FORTRAN IV compiler must have a bug, because my first simple program couldn't have any errors...
– RonJohn
Nov 17 at 5:23
"The computer must be wrong, because I obviously didn't make a mistake!" reminds me of when I complained that the FORTRAN IV compiler must have a bug, because my first simple program couldn't have any errors...
– RonJohn
Nov 17 at 5:23
add a comment |
2 Answers
2
active
oldest
votes
up vote
49
down vote
accepted
This is giving you the ISO week which begins on a Monday.
The ISO week date system is effectively a leap week calendar system that is part of the ISO 8601 date and time standard issued by the International Organization for Standardization (ISO) since 1988 (last revised in 2004) and, before that, it was defined in ISO (R) 2015 since 1971. It is used (mainly) in government and business for fiscal years, as well as in timekeeping. This was previously known as "Industrial date coding". The system specifies a week year atop the Gregorian calendar by defining a notation for ordinal weeks of the year.
An ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks. That is 364 or 371 days instead of the usual 365 or 366 days. The extra week is sometimes referred to as a leap week, although ISO 8601 does not use this term.
Weeks start with Monday. Each week's year is the Gregorian year in which the Thursday falls. The first week of the year, hence, always contains 4 January. ISO week year numbering therefore slightly deviates from the Gregorian for some days close to 1 January.
If you want to show 12/31 as week 52, you should use %U, which does not use the ISO standard:
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
$ date -d "2018-12-31T1:58:55" +"%U%a"
52Mon
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
answered Nov 15 at 20:29
Jesse_b
11.4k23063
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
add a comment |
up vote
3
down vote
The definition of the week number is different between Europe and the USA, probably ISO versus ANSI standards. This may be related to a week being Sunday--Saturday or Monday--Sunday, and this again may be related to the Jewish versus Christian definition of the Lord's Day (Sabbath vs Sunday).
For Europe, week number 1 contains the first Thursday in January, and thus it contains a minimum of 4 days (i.e. a majority) belonging to the new year (Thu-Fri-Sat-Sun).
Anyway, in such years when ALL (!!) week numbers are +/- 1 different between Europe and the USA this gives great fun with setting schedules in multi-national companies. :-)
answered Nov 16 at 12:17
StessenJ
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
49
down vote
accepted
This is giving you the ISO week which begins on a Monday.
The ISO week date system is effectively a leap week calendar system that is part of the ISO 8601 date and time standard issued by the International Organization for Standardization (ISO) since 1988 (last revised in 2004) and, before that, it was defined in ISO (R) 2015 since 1971. It is used (mainly) in government and business for fiscal years, as well as in timekeeping. This was previously known as "Industrial date coding". The system specifies a week year atop the Gregorian calendar by defining a notation for ordinal weeks of the year.
An ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks. That is 364 or 371 days instead of the usual 365 or 366 days. The extra week is sometimes referred to as a leap week, although ISO 8601 does not use this term.
Weeks start with Monday. Each week's year is the Gregorian year in which the Thursday falls. The first week of the year, hence, always contains 4 January. ISO week year numbering therefore slightly deviates from the Gregorian for some days close to 1 January.
If you want to show 12/31 as week 52, you should use %U, which does not use the ISO standard:
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
$ date -d "2018-12-31T1:58:55" +"%U%a"
52Mon
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
answered Nov 15 at 20:29
Jesse_b
11.4k23063
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
add a comment |
up vote
49
down vote
accepted
This is giving you the ISO week which begins on a Monday.
The ISO week date system is effectively a leap week calendar system that is part of the ISO 8601 date and time standard issued by the International Organization for Standardization (ISO) since 1988 (last revised in 2004) and, before that, it was defined in ISO (R) 2015 since 1971. It is used (mainly) in government and business for fiscal years, as well as in timekeeping. This was previously known as "Industrial date coding". The system specifies a week year atop the Gregorian calendar by defining a notation for ordinal weeks of the year.
An ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks. That is 364 or 371 days instead of the usual 365 or 366 days. The extra week is sometimes referred to as a leap week, although ISO 8601 does not use this term.
Weeks start with Monday. Each week's year is the Gregorian year in which the Thursday falls. The first week of the year, hence, always contains 4 January. ISO week year numbering therefore slightly deviates from the Gregorian for some days close to 1 January.
If you want to show 12/31 as week 52, you should use %U, which does not use the ISO standard:
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
$ date -d "2018-12-31T1:58:55" +"%U%a"
52Mon
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
answered Nov 15 at 20:29
Jesse_b
11.4k23063
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
add a comment |
up vote
49
down vote
accepted
up vote
49
down vote
accepted
This is giving you the ISO week which begins on a Monday.
The ISO week date system is effectively a leap week calendar system that is part of the ISO 8601 date and time standard issued by the International Organization for Standardization (ISO) since 1988 (last revised in 2004) and, before that, it was defined in ISO (R) 2015 since 1971. It is used (mainly) in government and business for fiscal years, as well as in timekeeping. This was previously known as "Industrial date coding". The system specifies a week year atop the Gregorian calendar by defining a notation for ordinal weeks of the year.
An ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks. That is 364 or 371 days instead of the usual 365 or 366 days. The extra week is sometimes referred to as a leap week, although ISO 8601 does not use this term.
Weeks start with Monday. Each week's year is the Gregorian year in which the Thursday falls. The first week of the year, hence, always contains 4 January. ISO week year numbering therefore slightly deviates from the Gregorian for some days close to 1 January.
If you want to show 12/31 as week 52, you should use %U, which does not use the ISO standard:
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
$ date -d "2018-12-31T1:58:55" +"%U%a"
52Mon
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
answered Nov 15 at 20:29
Jesse_b
11.4k23063
This is giving you the ISO week which begins on a Monday.
The ISO week date system is effectively a leap week calendar system that is part of the ISO 8601 date and time standard issued by the International Organization for Standardization (ISO) since 1988 (last revised in 2004) and, before that, it was defined in ISO (R) 2015 since 1971. It is used (mainly) in government and business for fiscal years, as well as in timekeeping. This was previously known as "Industrial date coding". The system specifies a week year atop the Gregorian calendar by defining a notation for ordinal weeks of the year.
An ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks. That is 364 or 371 days instead of the usual 365 or 366 days. The extra week is sometimes referred to as a leap week, although ISO 8601 does not use this term.
Weeks start with Monday. Each week's year is the Gregorian year in which the Thursday falls. The first week of the year, hence, always contains 4 January. ISO week year numbering therefore slightly deviates from the Gregorian for some days close to 1 January.
If you want to show 12/31 as week 52, you should use %U, which does not use the ISO standard:
$ date -d "2018-12-31T1:58:55" +"%V%a"
01Mon
$ date -d "2018-12-31T1:58:55" +"%U%a"
52Mon
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
answered Nov 15 at 20:29
Jesse_b
11.4k23063
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
edited Nov 17 at 12:43
Jeff Schaller
36.3k952119
36.3k952119
answered Nov 15 at 20:29
Jesse_b
11.4k23063
answered Nov 15 at 20:29
Jesse_b
11.4k23063
answered Nov 15 at 20:29
Jesse_b
11.4k23063
11.4k23063
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
add a comment |
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
Thanks. That is what I was looking for. I used a much more convoluted method with the cal command.
– George Shafer
Nov 16 at 21:10
add a comment |
up vote
3
down vote
The definition of the week number is different between Europe and the USA, probably ISO versus ANSI standards. This may be related to a week being Sunday--Saturday or Monday--Sunday, and this again may be related to the Jewish versus Christian definition of the Lord's Day (Sabbath vs Sunday).
For Europe, week number 1 contains the first Thursday in January, and thus it contains a minimum of 4 days (i.e. a majority) belonging to the new year (Thu-Fri-Sat-Sun).
Anyway, in such years when ALL (!!) week numbers are +/- 1 different between Europe and the USA this gives great fun with setting schedules in multi-national companies. :-)
answered Nov 16 at 12:17
StessenJ
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
3
down vote
The definition of the week number is different between Europe and the USA, probably ISO versus ANSI standards. This may be related to a week being Sunday--Saturday or Monday--Sunday, and this again may be related to the Jewish versus Christian definition of the Lord's Day (Sabbath vs Sunday).
For Europe, week number 1 contains the first Thursday in January, and thus it contains a minimum of 4 days (i.e. a majority) belonging to the new year (Thu-Fri-Sat-Sun).
Anyway, in such years when ALL (!!) week numbers are +/- 1 different between Europe and the USA this gives great fun with setting schedules in multi-national companies. :-)
answered Nov 16 at 12:17
StessenJ
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
3
down vote
up vote
3
down vote
The definition of the week number is different between Europe and the USA, probably ISO versus ANSI standards. This may be related to a week being Sunday--Saturday or Monday--Sunday, and this again may be related to the Jewish versus Christian definition of the Lord's Day (Sabbath vs Sunday).
For Europe, week number 1 contains the first Thursday in January, and thus it contains a minimum of 4 days (i.e. a majority) belonging to the new year (Thu-Fri-Sat-Sun).
Anyway, in such years when ALL (!!) week numbers are +/- 1 different between Europe and the USA this gives great fun with setting schedules in multi-national companies. :-)
answered Nov 16 at 12:17
StessenJ
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
The definition of the week number is different between Europe and the USA, probably ISO versus ANSI standards. This may be related to a week being Sunday--Saturday or Monday--Sunday, and this again may be related to the Jewish versus Christian definition of the Lord's Day (Sabbath vs Sunday).
For Europe, week number 1 contains the first Thursday in January, and thus it contains a minimum of 4 days (i.e. a majority) belonging to the new year (Thu-Fri-Sat-Sun).
Anyway, in such years when ALL (!!) week numbers are +/- 1 different between Europe and the USA this gives great fun with setting schedules in multi-national companies. :-)
answered Nov 16 at 12:17
StessenJ
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered Nov 16 at 12:17
StessenJ
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered Nov 16 at 12:17
StessenJ
1471
answered Nov 16 at 12:17
StessenJ
1471
1471
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
StessenJ is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
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9
"Date Command Gives Wrong Week Number for Dec 31" – "Wrong" according to which specification? Is the specification you are using the same one that the manual for
datesays it is using?– Jörg W Mittag
Nov 15 at 22:41
2
Excel week number inconsistent results, Excel weeknum function returns wrong week, UI calendar shows wrong week number
– phuclv
Nov 16 at 6:27
2
You might be interested in Why does the MonthCalendar control show the wrong week numbers in Romania? The blog post is about Windows, but the issue being discussed is general (and seems to be the same as what you are encountering).
– a CVn
Nov 16 at 10:25
1
"The computer must be wrong, because I obviously didn't make a mistake!" reminds me of when I complained that the FORTRAN IV compiler must have a bug, because my first simple program couldn't have any errors...
– RonJohn
Nov 17 at 5:23