# What does the fixed interval option do?

The fixed interval option can be selected when you create a:

- maintenance task.
- safety drill.

The following table clarifies what this option does.

A task or a drill has an interval of one month.

<table border="1" id="bkmrk-no-fixed-interval-fi" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 33.3731%;"></col><col style="width: 33.3731%;"></col><col style="width: 33.3731%;"></col></colgroup><tbody><tr><th style="background-color: rgb(230, 126, 35);">  
</th><th style="background-color: rgb(230, 126, 35);">**No fixed interval**</th><th style="background-color: rgb(230, 126, 35);">**Fixed interval**</th></tr><tr><td>Expiration date</td><td>1 January</td><td>1 January</td></tr><tr><td>Date of first execution</td><td>3 January</td><td>3 January</td></tr><tr><td>Next expiration date</td><td>3 February</td><td>1 February</td></tr><tr><td>Date of second execution</td><td>6 February</td><td>6 February</td></tr><tr><td>Next expiration date</td><td>6 March</td><td>1 March</td></tr></tbody></table>

With a fixed interval, the next expiration date is always calculated from the first expiration date.