To find the Monday of the week a date falls in, count how many days the date is after Monday and go back that many. With Weekday numbering Monday as 1, that's Weekday(date, StartOfWeek.Monday) - 1 days, and DateAdd goes back. For Sunday 8 November 2026 the result is Monday 2 November.

Weekday turns a date into the number of its day in the week. By default the week starts on Sunday, so Sunday is 1 and Saturday 7. Add StartOfWeek.Monday and Monday is 1 and Sunday 7, the way a UK week runs.

For a month with no entries, a Power Apps screen showed Total for September 2026: hours, with nothing where the number should be. Sum of a table with no rows returned blank, not 0, and Text turned the blank into empty text. Wrapping the Sum in Coalesce(…, 0) made it read 0.00 hours.

Every row of a Power Apps gallery showed a thin grey scroll bar at the end of its first two lines of text. The two Text controls were 24 pixels high and kept their default padding of 5 at the top and bottom, which left less room than one line of text needs. Setting PaddingTop and PaddingBottom to 0 removed the scroll bars.

This is the screen people use most: they log a shift of overtime. They choose the day it started, the start and finish times, the unpaid break, the department and a reason. The hours are worked out as they choose, correctly across midnight and the nights the clocks change, and Save stays disabled until the entry is complete and doesn't clash with one already logged.

To save a date to SharePoint with Patch, pass a Date to a date-only column and a DateTime to a date-and-time column, as values, not text. SharePoint then shows exactly what the person chose, as long as the site's time zone is the one they work in. A night shift saved this way showed as 24/10/2026 22:00 to 25/10/2026 06:00.

Saving to SharePoint takes a moment, and a second tap on Save in that moment runs its formula again: two items instead of one. Make setting a context variable the first thing OnSelect does, keep the button disabled and showing Saving... while the variable is true, and set it back when the save finishes, whether it worked or not.

When a screen is built from separate controls and saved with Patch, nothing checks the values for you. Two pieces do the job: a message that shows the first thing wrong, and a Save button that stays disabled until every field is filled in and there's nothing wrong. Put the rules in one place, and both pieces use them.

Two time ranges overlap when each one starts before the other ends. In a formula, that's StartTime < NewEnd && EndTime > NewStart. Put it in a LookUp on your list and you get the first entry that clashes with a new one, or blank when the time is free.

A user-defined function is a formula with a name and parameters. You write it once in App.Formulas, then call it from any control, exactly like a built-in function: ShiftMinutes(Date(2026, 10, 24), Time(22, 0, 0), Time(6, 0, 0)) returns 540. Change the function, and every control that calls it changes with it.