# Tip: Irregular Cycling

**URL:** <https://cylc.discourse.group/t/tip-irregular-cycling/1031>\
**Category:** Tips\
**Created:** [October 7, 2024, 9:36am UTC](https://cylc.discourse.group/t/tip-irregular-cycling/1031 "2024-10-07T09:36:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![oliver.sanders](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/oliver.sanders/32/110_2.png) [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\
**Post date:** [October 7, 2024, 9:36am UTC](https://cylc.discourse.group/t/tip-irregular-cycling/1031/1 "2024-10-07T09:36:18Z")

</div>

We typically schedule tasks on regular intervals, e.g. `P1D` (every day) or `PT1H` (every hour), however, sometimes our intervals are irregular. In the extreme, we might have a list of completely arbitrary dates to work with.

We can implement such workflows using Jinja2 to write out the recurrences we need. There is now a new example in the Cylc documentation showing how to do this, including a couple of tricks for working with irregular inter-cycle dependencies.

[https://cylc.github.io/cylc-doc/nightly\_8.4/html/user-guide/examples/cycle-over-irregular-dates/index.html](https://cylc.github.io/cylc-doc/nightly_8.4/html/user-guide/examples/cycle-over-irregular-dates/index.html)