Nightshift

So I work nights 7p-7:30a 3 nights a week and I am going to start taking my BM and charting it. What time should I take my temp on the days I work? After I wake up in the evening or should I just take it in my days off when I'm sleeping like a normal person? I feel like if I just do it on my days off I'm going to miss my ovulation day. Any suggestions will help a ton. I'm new at this, just started trying for a month.