I need to set a mask on a text box control for a time duration field in the format hh:mm.
hh runs be from 00 - 12 and mm can be from 00 to 59. The user can enter negative number to denote negative duration.
some examples of valid values are -12:23 12.23 01:00 12:00
I have the following regular expression, which partially works:
(0(\R.([0-1]\d|2[1-3])|\d)|1(\R.(0\d|1[0-1])|\d)|2\d|3[0-5])\R:[0-5]\d
However, I neeed to add to this expression for the user to add an option negative sign. How do I do this?