When the year is 29 or less, Excel will use the twenty-first century.
When the year is 30 or greater, Excel will use the twentieth century.
Let’s take a look.
Here we have a list of birthdays.
Our first three birthdays have a year that’s greater than 29.
The next three birthdays all have a year that’s less than 30.
In this case, we need to use a 4-digit year.
The last birthday is before January 1, 1900.
Excel doesn’t recognize this value as a date at all.
Instead, Excel treats thevalue as textand aligns the contents of the cell to the left.
