@Phineas - I am sure you have already followed some of these steps, but writing them all out for completeness:
1. Insert a Dropdown control into the DataCard for the DateTime field
2. In the Items property of the Dropdown control, enter:
["AM", "PM"]
3. Set the Default property of the above to:
If(
Hour(Parent.Default) < 12,
"AM",
"PM"
)
4. Modify the Items in the Hour Dropdown control to:
["12","01","02","03","04","05","06","07","08","09","10","11"]
5. Set the Default property of the Hour control to:
Text(
If(
Mod(
Hour(Parent.Default),
12
) = 0,
12,
Mod(
Hour(Parent.Default),
12
)
),
"0"
)
6. Set the DataCard Update property to:
If(
Not IsBlank(DateValue1.SelectedDate),
DateValue1.SelectedDate + Time(
If(
'Your AM-PM Dropdown'.Selected.Value = "PM",
12,
0
) + Mod(
Value(HourValue1.Selected.Value),
12
),
Value(MinuteValue1.Selected.Value),
0
)
)