In a UserForm I've got a TextBox asking for an amount of time (hours
and minutes). It could be negative. If the user wants to enter a
negative date, I want them to be able to just enter, for example:
-3:04, -10:53, etc. I'm in 1904 mode. My code for this value is:

Worksheets("Leave").Range("K5").Value = UserForm1.TextBox3.Value

I've tried inputting times like this: -3:04 and this: -"3;04", but
neither will do.