Description of problem:
logrotate won't do weekly rotation if last week's rotation was even 1 second later than this week's rotation. This is nearly impossible to do consistently, even if running logrotate directly from a crontab entry, and certainly impossible when run from /etc/cron.daily/logrotate as it is by default. The result is that weekly rotations which should occur on Sunday often don't happen until Monday morning. A hook in logrotate seems to reset things so that after a Monday rotation, the next one occurs on Sunday (weekday comparison in addition to time comparison).

Version-Release number of selected component (if applicable):
3.8.6-14

How reproducible:
Happens quite frequently.

Steps to Reproduce:
1. Wait for logrotate to run Sunday morning, then check later that day or the next.
2. ls -ltr /var/log/messages*
3. Look at the dates of the rotated log files.
4. Note that they're not always 7 days apart - some are on Monday rather than Sunday

Actual results:
-rw-------. 1 root root 20645073 Oct 16 04:18 /var/log/messages-20171016
-rw-------. 1 root root 17065169 Oct 22 04:17 /var/log/messages-20171022
-rw-------. 1 root root 15279183 Oct 29 07:45 /var/log/messages-20171029
-rw-------. 1 root root 14792166 Nov  6 04:44 /var/log/messages-20171106
-rw-------. 1 root root   325138 Nov  6 08:52 /var/log/messages

Expected results:
-rw-------. 1 root root 20645073 Oct 15 04:18 /var/log/messages-20171015
-rw-------. 1 root root 17065169 Oct 22 04:17 /var/log/messages-20171022
-rw-------. 1 root root 15279183 Oct 29 07:45 /var/log/messages-20171029
-rw-------. 1 root root 14792166 Nov  5 04:44 /var/log/messages-20171105
-rw-------. 1 root root   325138 Nov  6 08:52 /var/log/messages

Additional info:
This bug should be fixed in logrotate 3.12.0 or later. See https://github.com/logrotate/logrotate/releases/tag/3.12.0 for changelog (item "weekly rotations are now predictable and configurable (#93)). Updating to this version, or the latest upstream version, should fix this bug.

Alternatively, the test in logrotate.c should be patched to be less obsessive about what constitutes a week. The Debian bug report for this has a patch to allow 60 seconds of jitter, which might work if you only run logrotate at a consistent time from a crontab entry, but won't be sufficient for the often several hours of variability when running from cron.daily. Rather than 60 s, the jitter should be more like 6 hours (6 * 3600). See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=825776 for that attempted solution. (The follow-up discussion recommended the upstream fix instead.)