When sources are only available at certain times, please display the schedule

When using the FamilySearch Catalog recently, I have come across some online sources that are sometimes locked (requiring access at a Family History Center), and sometimes not. These sources all seem to relate to Colonial Virginia (tax lists, deed records, probate records, court records). I start doing research using these sources from my home, only to find that I can't access them the next time I try, but if I wait a little later I'm successful at getting in. It's a little frustrating.

It seems like I'm most successful at getting in on weekday evenings. My question is whether this toggling of access is a bug or if it is intentional? If it is intentional, is there in fact a schedule when these sources are unlocked to the public? If there is a schedule, is there some way that you can make it clear within the catalog when the source is open to the public and when it is not? That way, I could plan my research around that schedule.