REXX is a wonderful scripting language, but in itself lack a scheduler.
Actually, it isn't all that difficult to program a simple scheduler, but an alternative would be to use DragText to start the REXX, just before the first wakeup time (05:10), every day. Trigger your REXX to check what day it is. If it is a day when the alarm is supposed to happen then, wait for the proper time, and trigger the alarm (turn on the music, make noise, whatever). If it is a day to wake up at 06:00, or 08:00, set the appropriate sleep time, sleep, then trigger the alarm. A table of special days could also allow a different time for holidays (I would suggest that an alarm at 05:10, on New Years Day, would probably not be ideal).

If you want to use DragText, to trigger something at different times, you would need to have multiple icons (one for each day), or you would need to use REXX to change the schedule in that one icon, every day. The repeat time would need to change, or the trigger time would need to change. I don't know of any way to change those things with a program (WPTOOLS would be the way to do it, that I know about, but it doesn't know about those settings). You would still need to run some REXX (or something else) to make the change, every day, and that REXX would need to do the time math to figure out the proper settings. Easier to just run the REXX, and put it to sleep for the appropriate time periods, before or after checking the schedule. Of course, it would need to synchronize itself, when the program starts (after a boot, or whatever), and set an appropriate initial sleep time.
If there's a way to add it, then there's a way to remove the schedule as well, delete the program object or rewrite/update it, so it shouldn't be a problem once I get the info to create similar Objects for other use.
The WPTOOLS source is at netlabs:
ftp://ftp.netlabs.org/pub/wptools/. Inspecting that, may give you some idea of what to look for. Rich Walsh wrote DragText, but he seems to have left the OS/2 community. A polite message to him, might get some information.