When Jesus warned that no one knows their time when they will be called to account, and how it may come like "a thief in the night," this does not mean that people can play with their time of commitment to God in return.
It is not a smart idea to decide that you are going to "surprise God" with conversion when you are good and ready. While God understands that it is a process, and knows your heart and soul much better than you do, game playing with timing conversion and penance according to mundane, secular or worse occult reasons is a serious problem.
Those of you who have taught your children to think like that are going to have some serious explaining to do. I'm sick of seeing children of ex-hippies and New Age freaks postponing their salvation because their parents or aunts/uncles whoever whatever taught them to worry about Uranus.