About Timing
There are some stressful or difficult times when you may want to put off starting the toilet-teaching process — when traveling, around the birth of a sibling, changing from the crib to the bed, moving to a new house, or when your child is sick (especially if diarrhea is a factor). It may be better to postpone it until your child's environment is stable and secure.
Also, while some experts recommend starting the process during summer because kids wear less clothing, but it is not a good idea to wait if your child is ready.