Refactor/fix schedule definition again

without the postfix "every day" Renovate no longer seems to have very weird errors in its parsing code, resulting in pipelines running outside the schedule

Examples: "after 6pm and before 8pm every day" run today (aug 29) resulted in "9/1/2024, 6:00:00 PM" being the next valid window

How to test

1. go here
2. enter the old value after 6pm and before 8pm every day
3. see some invalid result
4. enter the new value after 6pm and before 8pm
5. see the correct result
6. go here
7. see that the above validator is listed as the recommended way to validate the schedule