Numbers might be tricky with TTS systems. Say you wrote 1979. Did you mean the year nineteen seventy nine, or did you mean the number one thousand nine hundred seventy nine?

The TTS system has no way of knowing perfectly. It will guess to the best of its abilities from the context, but it will get it wrong at times.

Therefore, for numbers, if you are facing an issue, the best practice is to write it out into English.

Phone numbers

958-2910-2992 =>nine five eight, two nine one zero, two nine nine two

Date

10/29/1992 => October twenty ninth, nineteen ninety two

1990s => nineteen nineties

80s => eighties

Time

9:10 AM => Nine ten A M

Decimals

69.39 => sixty nine point three nine