I was asked on how to split a string from a textbox to its given hour and minute values.

let x='22:12'.split(':'.tochararray) in
(
  Integer.Parse(x.at0(0)).asstring+' hours and '+Integer.Parse(x.at0(1)).asstring+' minutes'
)

Why you may ask? Well consider to have this in a ReverseDerived string representing the clock. Once you have the parts you can update a datetime value with thes for storage

Or maybe like this:

let x='22:12'.split(':'.tochararray) in(
  DateTime.Parse('0001-01-01 '+x.at0(0)+':'+x.at0(1))
)

I later found that another article addresses the same issue in a wider context together with the derived settable attribute here Derived settable attributes.