Michael,

This thread has been primarily about RTC type timing requirements. In this situation it doesn't matter what the period of the timer interrupt actually is provided that it is predictable. You can afford to choose a reload value simply because the low byte is zero.

As it happens the oscillator frequencies that are good for baudrates tend to be good for generating timer tick periods that are convenient fractions of a second with a zero low reload byte. As we all choose oscillators that give 0% baudrate error (don't we?) we get the best of both worlds.

Oleg's solution is not only elegant but it is also the simplest.