This function returns the serial number of a date entered as text.
DATEVALUE(date_string)
The argument for this function is a date as a string.
Use this function to convert a date represented by a text string to an Excel serial number that can be used to perform calculations.
Accepts string data. Returns an excel serial number as date.
DATEVALUE(B18)
DATEVALUE(R18C2)
DATEVALUE("2019/02/13") gives the result 43509.
This function is available in product version 1.0 or later.
DATE | TIMEVALUE | Date and Time Functions