Good news about The Shield is that it is repeated many times
throughout the week on FX. I searched for next week's (Tuesday, April
26) episode of The Shield and found that it will air Tuesday April 26,
at 10pm and at 11pm, Friday April 29 at 11pm, Sunday May 1 at 10pm,
and Monday May 2 at 10pm. It appears to be the same schedule every
week, so you can remember the following days/times:
Tuesday: 10pm, 11pm
As for 24, unfortunately it is only shown once per week on Fox and the
current episodes are not shown on any other channel. My suggestions
would include taping it, using a PVR (Tivo, etc), or if you have the
option, with satellite TV you would be able to watch it later that
night from a station in a different time zone.
To find this information I used the listings available at TVGuide.com.
If you create a profile and then click on the show that you would like
to watch in the listings table, a tab will appear on the left with
additional airings of that show throughout the week.
tv guide ://www.google.com/search?q=tv+guide