How does excel keep two decimal places?

Excel reserves two decimal places:

How to round in excel is to adjust the cell format and select two decimal places (the same is true for reducing decimal places in the menu bar); It is also realized by rounding function round.

If it is the former, it just seems to retain two decimal places, but the essence of the cell is still a lot of digits after a decimal point. If it is the latter, it really retains two decimal places. Therefore, it is suggested that there will be no tail difference in the data under the circular function specification. skill

Open the data table of the contract record form, which contains information such as customer name, signing time and expiration time. Now we need to merge the date under the signing time column and the date under the expiration time column into a start date.