I haven't done this but have been thinking about it and came to the conclusion that I would be being unreasonable. Mostly because if i'm off, my colleagues cop for a little bit of my workload and one poor colleague would have to work a 12 hour day.
I am feeling very tired lately, quite rundown and I could really do with a duvet day. On my one day off I have to go and visit relatives so don't even get to rest then and the 3 hour daily commute gets me down. Is it ok to have a day off work just because of tiredness?