Bug #77941 [ReO->Nab]: strtotime "next <weekday>" are off by one for dates parsed from calendar week
Edit report at https://bugs.php.net/bug.php?id=77941&edit=1
ID: 77941
Updated by: derick@php.net
Reported by: mail at cebe dot cc
Summary: strtotime "next <weekday>" are off by one for dates
parsed from calendar week
-Status: Re-Opened
+Status: Not a bug
Type: Bug
Package: Date/time related
Operating System: Linux
PHP Version: 7.3.4
Block user comment: N
Private report: N
New Comment:
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
The combination of the "yyyyWww" and "x dayname" stanzas is not supported.
However, in order to find the Friday of a week, you can use "yyyyWww-d", such as
"2019W16-5". We can't support every string that you throw at the parser :-).
Previous Comments:
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[2019-06-14 11:52:02] sjon@php.net
Related To: Bug #77999
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[2019-04-25 21:17:45] cmb@php.net
Seems I closed this too quick â sorry. Re-opening.
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[2019-04-25 21:04:51] a at b dot c dot de
How would using the ISO year make a difference in the middle of April? And why would it cause a
shift of one day?
Consider
echo date("o-W-N", strtotime("2019W16 next tuesday"));
Between 5.1.6 and 5.2.0 the output changes from Tuesday of Week 16 (2019-16-2) to Monday of Week 17
(2019-17-1).
Tuesday isn't Monday even in the ISO calendar.
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[2019-04-25 13:21:34] cmb@php.net
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
You have to use 'o' in combination with 'W'.
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[2019-04-25 09:25:25] mail at cebe dot cc
Description:
------------
when working on a date parsed from calendar week from the pattern {YYYY}W{WW}, e.g.
"2019W16" strtotime returns the date of Monday in the calendar week 16 in the year 2019,
which is 2019-04-15.
When this is combinated with a "next <weekday>" e.g. "2019W16 next
friday", the result is one off, in this case 2019-04-18, which is Thursday of that week, not
Friday.
Giving "2019-04-15 next friday" gives the correct date: 2019-04-19.
According to my test script, this is broken since PHP 5.2, while working fine in 5.1: https://3v4l.org/0s4Ns
Test script:
---------------
<?php
// see also https://3v4l.org/0s4Ns
if (function_exists('date_default_timezone_set'))
date_default_timezone_set("UTC");
echo "works as expected:\n";
echo date("Y-m-d H:i:s", strtotime("2019W14")) . " should be
2019-04-01\n";
echo date("Y-m-d H:i:s", strtotime("2019W15")) . " should be
2019-04-08\n";
echo date("Y-m-d H:i:s", strtotime("2019W16")) . " should be
2019-04-15\n\n";
echo "off by one:\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next tuesday")) . " should be
2019-04-16\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next wednesday")) . " should be
2019-04-17\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next thursday")) . " should be
2019-04-18\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next friday")) . " should be
2019-04-19\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next saturday")) . " should be
2019-04-20\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next sunday")) . " should be
2019-04-21\n";
echo date("Y-m-d H:i:s", strtotime("2019W16 next monday")) . " should be
2019-04-22\n\n";
echo "works as expected:\n";
echo date("Y-m-d H:i:s", strtotime("2019-04-15 next monday")) . " should be
2019-04-22\n";
echo date("Y-m-d H:i:s", strtotime("2019-04-15 next friday")) . " should be
2019-04-19\n";
echo date("Y-m-d H:i:s", strtotime("2019-04-15 next thursday")) . " should
be 2019-04-18\n";
Expected result:
----------------
see above.
Actual result:
--------------
see above.
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Edit this bug report at https://bugs.php.net/bug.php?id=77941&edit=1
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