Is there a single word that defines time is on your part/side/favor?
You might consider serendipity. NOAD says:
serendipity (n.): the occurrence and development of events by chance in a happy or beneficial way
Alternatively, you could also say these are fortuitous events. Macmillan defines fortuitous as:
fortuitous (adj.): happening by chance, especially in a way that is lucky or convenient
These words aren't restricted to incidents when "time is in your favor," as was mentioned in your original question, but having especially good timing through sheer blind luck could be one way to experience serendipity.