It's the amount of daylight that sets off the rut, but in conjunction with the moon it can and does effect daylight movement. Your ideal would be to have a blackout on the 14th or so. If it's a full blown neon moon, you can look for more movement during midday than at first and last light. I haven't looked, but probably optimum movement will be like 8 or 9 at night and 2 or 3 in the AM and then 11-1 or so during the day