PHP Excel Reader, Excel time converted to PHP time format

Recently, I was doing an import function, using the Phpexcel class library in the system, reading the uploaded Excel file, then mapping the fields, and finally importing the data in Excel into the system. Among them, about the date format of the import, make me make a difficult.

First, how to import the date, because the date format in the Phpexcel is obtained by the number, not the date string, so there is a lot of code on the Internet to convert the numbers obtained in Excel into the Unix time used by PHP, in fact, it does not have to be so troublesome. In Phpexcel, there is this method: phpexcel_shared_date::exceltophp ($value). can be used directly.

The resulting results can then be converted into dates using the data function.