ambiguous ...

Birthday mainly refers to heavenly stems and earthly branches when he was born.

For example: year, month, day and hour.

Jiazi is ugly and ugly, Jiazi is heavenly stem, and Jiazi is earthly branch, which consists of eight characters, referred to as "eight characters".

The so-called eight-character ambiguity means that you can't remember a time unit (year, month and day) and it can't be established.