Thank you for your comments and of course you were right, what I was looking for doesn’t seem possible using deep sleep. Due to the temperature drift of the RTC. In the limited time I’ve been testing the devices available to myself I sometimes get as much as 10 minutes error(usually it is a lot less than this), over the period of two hours. But thanking you again for your comments and again I have learned something new.
Thank you your time and trouble.