difference between two dates mysql code example

Example 1: mysql datediff days

#Get date diff in days
select DATEDIFF('2020-04-13', '2020-04-20');#returns -7
select DATEDIFF('2020-04-20', '2020-04-13');#returns  7

Example 2: mysql compare work days

5 * (DATEDIFF(@E, @S) DIV 7) + MID('0123444401233334012222340111123400001234000123440', 7 * WEEKDAY(@S) + WEEKDAY(@E) + 1, 1)