Scheduling a job one out of two Tuesdays

[badrAZ]

Currently, it's not possible to implement this feature request because cron doesn't keep executions in memory.

[julien-f]

A cron pattern is memory-less, it only checks whether the date matches the pattern, without any knowledge of the previous occurrence, and intervals are only handled in term of divisibility regarding to the unit they are applied to.

For instance a day of month of */2 means the 2nd, 4th, … and 30th days of the month. For months which does not have an even number of days (28 or 30) this will not work correctly as the job will not run on the 31st and again on the 1st, which is not the same as every two days.

A solution would be to have an alternative method of scheduling based on start date and a repeat pattern (every n day/week/month). It could be interesting to combine this with a cron pattern, either to specify on which week-day it should be run or the minute/hour scheduling during the matching days.

[julien-f]

Systemd could be an inspiration:

• https://trstringer.com/systemd-timer-vs-cronjob/
• https://www.freedesktop.org/software/systemd/man/systemd.time.html