Can I ask why the following results in the wrong reminder time?
every 14 days starting 17 sep at 7am results in the correct day but the time going to 23:59.
The issue is caused by attaching the time to the starting date and not the task itself.
The correct due date formula is: "every 14 days at 7am starting 17. Sep" (or Sep 17, depending on your date format). That is - the main formula for the task needs a due time.
Fantastic - thanks.