The toTime(...) function has four variations, not counting syntax variations.  You can convert a String to a Time with optional custom format string.  You can also convert a DateTime to a Time with an optional time zone.

Syntax:
toTime( time-string )
toTime(
time-string, format-string )
toTime(
dateTime )
toTime(
dateTime, timezone-string )
time-string.toTime()
time-string.toTime( format-string )
dateTime.toTime()
dateTime.toTime( timezone-string )

 

Parameter Description
time-string The String value to be converted to a Time value
format-string The format string is used to interpret the time-string. If omitted the default format is "h:mma" which is the hour then a colon, then the minute, then either "AM" or "PM".  For a description of possible format-string values refer to the Java API documentation for SimpleDateFormat.
dateTime The DateTime value to be converted to a Time value
timezone-string The time zone string is used to convert the dateTime value to a Time.  If omitted, the current user's preferred time zone is used.  Any time zone identifier supported by Java is allowed.