http://feldoncentral.com/garden/tomato_timeline.html

This is for beefsteak varieties, probaby much faster for cherry.

If it's hot, maybe never. If nighttime temps stay above 75F, fertilization won't happen, and the flowers will abort. Welcome to southern gardening.

Agree with Dan. Your question implies you think every blossom (what you called bud) will turn into a fruit. In fact, if you are lucky, due to all the variables only about 20-25% of them will ever be pollinated and develop fruit. It is only once a small green fruit forms that the Timeline linked above comes into effect.

Dave