Here is a function for anyone who is trying to do something similar--it takes times formatted as strings (such as 10:00 AM), and convert to date/time for calculation, such as adding 2 hours.

Convert string to date/time:

1. date TextTimetoRealTime(string texttime, date newdate)
2. {
3.     //This function takes a time string formatted with AM/PM (ex 2:30 PM) and converts it to a real time/date.  Arguments are the source of the time string, and some date field or variable.
4.     //RETURNS DATE ONLY IF NO AM/PM ON STRING.  
5.     //Parse time string 
6.     //Minutes
7.     varMin = (input.texttime.getSuffix(":")).getPrefix(" ");
8.     //AM/PM
9.     varAMPM = (input.texttime.getSuffix(":")).getSuffix(" ");
10.     //Hour (adds 12 hours if PM)
11.     varHour = input.texttime.getPrefix(":");
12.     if (varAMPM  ==  "PM")
13.     {
14.         varMilitaryHour = (varHour.toLong()  +  12);
15.     }
16.     else
17.     {
18.         varMilitaryHour = varHour.toLong();
19.     }
20.     //Parse real date and convert to strings
21.     //Month
22.     varMonth = (input.newdate.getMonth()).toString();
23.     //Day
24.     varDay = (input.newdate.getDay()).toString();
25.     //Year
26.     varYear = (input.newdate.getYear()).toString();
27.     //Puts date and time strings in correct format for converstion to date/time
28.     varStringDateandMilitaryTime = varMonth + "/" + varDay + "/" + varYear + " " + varMilitaryHour + ":" + varMin + ":00";
29.     varRealDateTime = varStringDateandMilitaryTime.toTime();
30.     return varRealDateTime;
31.     //<comment>
32. }