In reply to mjbeckett: Climb in the morning before work or in your days off.
Swap shifts with workmates to have 2 days off in a row.
Finding partners with the same rota is what is difficult, so soloing may be your only way.
If you miss most of your day off sleeping, then consider travelling to the crag in the evening, bivying, and then climb in the morning and try to make it back straight to work in the evening.
In winter i regularly maximise days off by going to Scotland straight after work and going straight back to work 2 days later.