VBScript DateDiff

DateDiff(interval,date1,date2[,firstdayofweek[,firstweekofyear]])

Notes:

1. interval ‘m’ stands for month, use ‘n’ for seconds

2. returns a negative nubmer if date1 < date2, otherwise, positve

Parameter Description
interval The interval you want to use to calculate the differences between date1 and date2
Can take the following values:

yyyy – Year
q – Quarter
m – Month
y – Day of year
d – Day
w – Weekday
ww – Week of year
h – Hour
n – Minute
s – Second