Hello everyone.
I followed @ShaneYoung 's videos on datediff for calulating and created a component to allow me to transfer the text version of the datetime to SharePoint. I need the date component since the timekeeping we do includes a night tour that rolls into the next day, and we would need to calculate the total time.
In creating the datediff between time and using the mod to create the hh:mm format, I ran into an issue with the minutes between :00 and :09. Those differences would yield something like this: 12:1 or 2:9 (12 hours and 1 minute, 2 hours and 9 minutes).
Question: How can append a 0 for the minutes?

RoundDown(DateDiff(STDATETIME_START.'24FullDateTime',STDATETIME_END.'24FullDateTime',Minutes)/60,0) & ":" & Mod(DateDiff(STDATETIME_START.'24FullDateTime',STDATETIME_END.'24FullDateTime', Minutes),60)