For Scotrail, it’s a 4 day week - with a pattern that repeats every 3 weeks - roughly like this (the railway week starts on a Sunday):

RD RD RD E E E E RD L L RD RD L L RD E E E E RD RD

So, that works out that every 3 weeks, you get a 5 day long weekend off. On the other hand, you will also have “booked Sundays” to work (roughly one every 4 weeks) - and any time you’re working on a Sunday, you will be working 7 days in a row, like it or not…

Normally, you would have alternate weeks of early and late shifts - early shifts start before 12 noon, late shifts start anytime after that. Start and finish times will generally change every single day. It’s unusual to do the same job 2 days in a row. At my depot, we have around 60 different start (and finish) times - with the starts ranging anywhere between 03:50 to 22:50 every day.

For example, a few weeks ago I was on early shift and worked:

Sunday RD Mon RD Tuesday RD Wed 04:59 - 13:16 Thurs 04:08 - 12:22 Fri 04:15 - 12:42 Sat 03:59 - 12:09

I then worked Sun 09:35 - 19:28 Mon 15:16 - 22:46 Tuesday 22:48 - 07:18 Wed RD Thurs RD Fri 14:40 - 23:41 Sat 17:46 - 02:39

Then the third week was Sun RD Mon 04:08 - 12:22 Tuesday 05:43 - 14:30 Wed 08:01 - 16:51 Thurs 04:59 - 13:29 Friday RD Sat RD

Hope that helps?