What do the numbers on the tickers mean?

The numbers on the tickers stand for months. The number sits in the middle of the month unit. The slider moves along according to the months, weeks and days, not the years.

For a ticker that is counting up, eg. a Child's Age ticker in the Lilypie Birthday section. The numbers count up from 1 to 12. For instance, if the child is 5 years and 3 months. The slider will be at the end of the 3 month unit.
Child's age 5 years and 3 months

For a ticker that is counting down, eg. a Next Birthday ticker. The numbers count down from 12 to 1. For instance, for a next birthday ticker if the birthday is in 9 months. The slider will be at the beginning of the 9 month unit.
Next birthday in 9 months
Because the slider moves along according to the months, weeks and days you can always see how close the next event is.