It depends on the chicken. Some will lay at the same time everday, and some don't. My banty hens are very unpredictable, might get an egg by 9am or as late as 4pm, or none at all. I think they like to surprise me . You might have a good hen that will lay at the same time everyday.
I'm not sure about all of my hens cuz I just got too many....LOL..
However, my spanish bantam is on a schedule.... she was a 6 day layer with the 7th off for her first year...now she's every other day with an occasional 2 day in a row lay(she's 2 now)....with her, if she laid one in the early morning...the next day would be about 2-3 hours later than that time and then next day 2-3 hours later than that time....etc until she was laying into the early evening...then the day off with no egg and then the early morning start again... she was so predictable.
Generally speaking, I believe that chickens lay every 26 hours or so, which would tend to have them laying at different times of day. But I've read where others say their birds lay every morning. So...I dunno. But I have four whose times vary.
If your RSL is of production, commercial stock, which is most likely, they are bred to lay everyday and most often in the AM. This trait is bred into the commercial type hen. Our RSLs lay every morning before 9 am. We had ISA Browns, another commercial strain, that laid everyday by 8 am, or they didn't lay that day at all, which is a rare event for an ISA.
The whole 26 hour cycle thing doesn't often apply to these RSLs. Our black sex links did seem to follow that trend and also took a day off more often.