Hi Mahalakshmi,
The Off-set is used to capture a part of existing string. Actually SY-DATUM hold the system date and its data type is of Char and length 8 with format YYYYMMDD.
So, now if we want Year from System date, we need to capture first four characters, so counting from 0 we need frist four. So, YEAR = SY-DATUM+0(4).
Same, for Month we need to capture 2 character from 4 (as count starts from 0).
MONTH = SY-DATUM+4(2).
Same for date, DATE = SY-DATUM+6(2).
Hope you got my explanation.
Regards,
Vijay