While defining Attendace type maintain validity period start date as 01.08.2015 so that it won't be available before 01.08.2015.
Further with the help of constants we can control in the PCR.
Define a constant in table V_T511K make the entry as 01.08.2015 as "1" before 01.08.2015 maintain it as blank Query the same in PCR.
NUM=KXXXX
NUM?1
<
= Here you can write your logic to update time type.
Regards
Venkatesh