I work as a flight attendant and as a result was going crazy about how to accurately chart my BBT. I got this tip from www.fertility friend.com. I hope it helps
How can I chart my BBT if I work shifts?
It is not impossible to take your BBT if you work shifts, but it will be more challenging. Take your temperature at the time you wake up when you are most likely to have had the most sleep. Be as consistent as you can. On your days off, take your temperature after you wake up as well, even if it is at a different time. Make a note on your chart of changes in your waking schedule. You may take your temperature in the afternoon before you go to work if that is your usual waking time and the time after which you are most likely to have had the most sleep. It is not useful to take your temperature when you are already awake and active.
How can I take my BBT when I am traveling?
If you travel within your own time zone, just keep on taking your temperature at the same time. You may notice a slight fluctuation if the climate is warmer/colder but this should not have a huge impact on your chart. Make a note in the notes section that you were traveling so you can explain unusual temperature patterns.
If you are traveling to a different time zone, the disturbance is usually only limited to the day of travel and the day after. Keep taking your temperature as before, using the same time in the local time. We recommend not adjusting any temperatures, but again, make a note of the circumstances. Unless you are traveling right around the time of ovulation, you should still be able to discern your pattern. When BBT is less reliable because of such a special circumstance, pay extra close attention to your other fertility signs to avoid missing a potential fertile opportunity.View Thread