strftime reference for Win32

The Posix-module has a very nice function called strftime() that is capable of formatting dates and times to a human readable format.

But ... the manpage is not very descriptive. It tells you nothing about the meanings of the parameters in the format string.

Unix/Linux users can read about them by typing

$ date --help
[download]

(thanks blokhead for advising me on that), but Windows users are lost.

Therefore, in the hope it will help somebody*, i post this little script, that can serve both as a reference and as an example.

use strict;
use POSIX qw(strftime);

print strftime qq{
a: Day of Week    (short, text) %a
A: Day of Week     (long, text) %A
b: Monthname      (short, text) %b
B: Monthname       (long, text) %B
c: Full datetime (number, long) %c
d: Day                 (number) %d
H: Hour (24 hour)      (number) %H
I: Hour (12 hour)      (number) %I
j: Day of year         (number) %j
m: Month               (number) %m
M: Minutes             (number) %M
p: am/pm/empty           (text) %p 
S: Seconds             (number) %S
U: Week of Year        (number) %U
w: Day of week         (number) %w
W: Week of Year        (number) %W
x: date                (number) %x
X: time                (number) %X
y: year         (short, number) %y
Y: year          (long, number) %Y
Z: timezone              (text) %Z
},
localtime;
[download]

Notes:
The parameters %U and %W, are not identical. %U starts counting the Week Of Year at sundays, %W starts counting on mondays.
The %p parameter can be empty, depending on the locale of the system.

*and for my own convenience

Update: corrected typo for %M
Update: corrected typo for %I (thanks bmann)
Update: retitled node from "strftime reference" to "strftime reference for win32"

holli, /regexed monk/

Comment on strftime reference for Win32 Select or Download Code

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Re: strftime reference by bmann (Priest) on Feb 24, 2005 at 18:40 UTC
holli++ - very useful For the sake of completeness, here's sample output: a: Day of Week (short, text) Thu A: Day of Week (long, text) Thursday b: Monthname (short, text) Feb B: Monthname (long, text) February c: Full datetime (number, long) 02/24/2005 12:53:26 PM d: Day (number) 24 H: Hour (24 hour) (number) 12 I: Hour (12 hour) (number) 12 j: Day of year (number) 055 m: Month (number) 02 M: Minutes (number) 53 p: am/pm/empty (text) PM S: Seconds (number) 26 U: Week of Year (number) 08 w: Day of week (number) 4 W: Week of Year (number) 08 x: date (number) 02/24/2005 X: time (number) 12:53:26 PM y: year (short, number) 05 Y: year (long, number) 2005 Z: timezone (text) Pacific Standard Time [download] Update: This is a Win2K system, Locale set to English(US)	[reply] [d/l]
Re^2: strftime reference by holli (Abbot) on Feb 24, 2005 at 18:44 UTC
Yes, I did not think of that. Here is the output for a german system. a: Day of Week (short, text) Do A: Day of Week (long, text) Donnerstag b: Monthname (short, text) Feb B: Monthname (long, text) Februar c: Full datetime (number, long) 24.02.2005 19:42:04 d: Day (number) 24 H: Hour (24 hour) (number) 19 I: Hour (12 hour) (number) 07 j: Day of year (number) 055 m: Month (number) 02 M: Minutes (number) 42 p: am/pm/empty S: Seconds (number) 04 U: Week of Year (number) 08 w: Day of week (number) 4 W: Week of Year (number) 08 x: date (number) 24.02.2005 X: time (number) 19:42:04 y: year (short, number) 05 Y: year (long, number) 2005 Z: timezone (text) Westeuropäische Normalzeit [download] As one can see, %p is empty here, because the locale is set to 24 hours. %x, %X and %c are different too. holli, /regexed monk/	[reply] [d/l]
Re^2: strftime reference by Anonymous Monk on Jun 26, 2010 at 02:20 UTC
Check out http://strfti.me for a very readable online reference and sandbox where you can experiment with different strftime format strings.	[reply]
Re: strftime reference by Joost (Canon) on Feb 24, 2005 at 23:47 UTC
but Windows users are lost. When I need to check a Unix syscall and don't have a nix machine ready, I usually type "man (pagename)" in google. It tends to work. "What should it profit a man, if he should win a flame war, yet lose his cool?"*	[reply]
Re: strftime reference by lachoy (Parson) on Feb 24, 2005 at 21:17 UTC
FWIW, the DateTime can translate an object to a string using strftime formats as well. (It's also got a guide to strftime formatting keys in the pod.) Plus with DateTime::Format::Strptime you can use the same format to parse a string into a DateTime object. It also does tons of other hugely useful date stuff. Chris M-x auto-bs-mode	[reply]
Re^2: strftime reference by astroboy (Chaplain) on Feb 24, 2005 at 21:56 UTC
Alas, there appears no ppd for this module, so Windows users are probably out of luck. The PPM::Repositories module returns `datetime http://datetime.perl.org/download Get your DateTime modules here` [download] but, alas, it didn't work for me...	[reply] [d/l]
Re^3: strftime reference by lachoy (Parson) on Feb 24, 2005 at 23:17 UTC
Check out the theoryx repository (which you can add with the URL: 'http://theoryx5.uwinnipeg.ca/cgi-bin/ppmserver?urn:/PPMServer58') -- the versions they have seem to be a little old, but it's still better than POSIX... Chris M-x auto-bs-mode	[reply]
Re: strftime reference by trammell (Priest) on Feb 24, 2005 at 22:52 UTC
When I do a `man strftime`, I get: The following conversion specifications are supported: %a Replaced by the locale's abbreviated weekday name. %A Replaced by the locale's full weekday name. %b Replaced by the locale's abbreviated month name. ... Maybe you just need to install better man pages? If you were doing a `perldoc POSIX`, I sympathize... Update: To be fair, the `POSIX` perldoc contains the text: Consult your system's "strftime()" manpage for details about these and the other arguments.	[reply]
Re: strftime reference by blahblahblah (Priest) on Feb 24, 2005 at 19:30 UTC
This is great. I could have used this a while back when I changed my date-time format in my perlmonks user settings. Perhaps tye could update New timezones and datetime format (instructions that are linked to from the user settings page) with a link to your reference.	[reply]
Re: strftime reference by demerphq (Chancellor) on Feb 25, 2005 at 17:34 UTC
Note that strftime format strings are system dependent. You normally should use your systems C documentation to find out what the possible formats are. On Win32 this means using MSDN. --- demerphq	[reply]
Re: strftime reference by Anonymous Monk on Feb 28, 2005 at 11:03 UTC
The reason that POSIX manual doesn't show the list of escape sequences is that the list depends on your OS. Perhaps you should make it more clear that your program is only of use for Windows users - on my system, I also have: %C: Century number (2 digits) %D: equivalent to %m/%d/%y %e: like %e, leading zero of month replaced with space %E: Modifier alternative format %F: Equivalent to %Y-%m-%d %g: Like %G, but use 2-digit year %G: 4 digit year, but if ISO week belongs to previous year, use previous year. %g: Like %G, but use 2-digit year %h: Equivalent to %b %k: Hours, 0 - 23, single digits preceeded by blank %l: Hours, 1 - 12, single digits preceeded by blank %n: Newline %O: Modifier alternative format %P: As %p, but in lowercase %r: Equivalent to '%I:%M:%S %p' %R: Equivalent to '%H:%M' %s: Number of seconds since epoch %t: Tab character %T: Equivalent to '%H:%M:%S'. %u: Day of week, 1 (Monday) - 7 (Sunday) %V: ISO week number of the year (01 - 53) %z: Time zone as offset of GMT. %%: A % character %+: Time in 'date' format Here's a program to see what's available on your OS: `#!/usr/bin/perl use strict; use warnings; use POSIX; foreach my $ch ('a' .. 'z', '%', '+') { my $lc = strftime "%\l$ch", localtime; my $uc = strftime "%\u$ch", localtime; for ($lc, $uc) { s/\n/\\n/g; s/\t/\\t/g; } printf "%%%s %25s %25s\n", lc $ch, $lc, $uc; } __END__` [download]	[reply] [d/l]
Re^2: strftime reference by holli (Abbot) on Feb 28, 2005 at 14:02 UTC
I was not aware of that. Thanks for the info, i retitled the node. holli, /regexed monk/	[reply] [d/l]
Re: strftime reference by bart (Canon) on Feb 25, 2005 at 15:13 UTC
For these your legend doesn't look quite right: `c: Full datetime (number, long) 25/02/05 16:10:05 x: date (number) 25/02/05 X: time (number) 16:10:05` [download] These aren't what I'd call "numbers"	[reply] [d/l]