I don't remember when it was introduced, either in JMP16 or 17. You can maybe still do it with Informat/Format but I'm not sure how as time handling was clunky in JMP before format pattern (and it still is due to how it handles different time formats on different machines with different settings). So I would build it from parts, this might work
Names Default To Here(1);
template = "^hh12^:^mm^:^ss^ ^ampm^";
str = "130749";
hh24 = Num(Left(str, 2));
mm = Substr(str, 3, 2);
ss = Right(str, 2);
ampm = "";
If(hh24 == 0,
hh12 = 12;
ampm = "AM";
, 12 <= hh24 <= 23,
hh12 = Mod(hh24, 12);
ampm = "PM"
,
ampm = "AM";
hh12 = hh24;
);
timestr = Eval Insert(template);
-Jarmo