Timing of your ovulation is a big issue when you are trying to conceive. Fertility awareness method, that we teach, can help you to find the exact day when you are ovulating.
If you want to be even more specific with the timing, there is interesting data from the studies. Aprently ovulation occurs primarily in the morning during Spring, and primarily in the evening during Autumn and Winter. From July to February in the Northern Hemisphere (I guess that would be from March to July in Southern Hemisphere) about 90% of women ovulate between 4 and 7PM; during Spring, 50% of women ovulate between midnight and 11AM.
We like it or not our bodies respond to seasonal changes. And not only women, guys reproductive systems are affected by it as well. Human sperm swim best and is healthiest in Winter and Spring.
Testart J, Frydman R, Roger M, Seasonal infl uence of diurnal rhythms in the onset of the plasma luteinizing hormone surge in
women, J Clin Endocrinol Metab 55:374, 1982.