The numbers 11, 29, and 1129 are wonderful numbers. 11 and 29 have their own web pages about their numerology essence and meanings and an overview of 1129 can be obtained at one of the calculators at this website. Click these links for the information.

The number 11.

The number 29.

The number 1129.

You may be seeing 11:29 as often as you do because it represents your oldest son's birthday. Like does attract like. However, simply a time/birthday correlation probably isn't enough to orient your attention to a clock at that time almost every day.

If you've been caught up in wondering what it means that you're seeing 11:29 on the clock so often, the mystery itself may be the reason for the seeings.

When there's a mystery, the mind finds it hard to let it go. Mysteries seem to require solution. Even when the conscious mind is focused on something else, the subconscious still tries to help you solve the mystery. It does so by trying to direct the focus of the conscious attention to instances of the mystery when they occur in the immediate environment. Thus, your attention is pulled to clocks when the time is 11:29.

All that doesn't negate the very real possibility of a personal meaning associated with seeing the time as often as you do. See the articles linked at the index to repetitively seeing certain numbers page for information about ferreting out the answer.