Should be

CTOT( "01/01/2000 " + ApptRules.EndTime)

Leave a space between year and time.

>I have this:
>
>

>ApptRules.EndTime = "02:45 PM"
>
>CTOT( "01/01/2000 : " + ApptRules.EndTime)
>

>
>The result is:
>
>

>01/01/2000 12:02:45 PM
>

>
>When I thought it would be:
>
>

>01/01/2000 02:45 PM
>