PCR For time Schema

Hello Experts,

our company wants to change the time interval of late coming, short leave and half day for the employees with flextime worksschedule. i am new to SAP HCM, i have read some threads on scn but could not understand them, please help me how to write rule and how to add it in Schema.

Timings are as follows:

Late coming: starts from 1 hour and 15 minute after start time.

Short leave: starts after 2 hours from start time & 2 hours before end time

Half day: starts after 4 hours

Thanks in advance,

waiting for your kind reply

Regards,

Muhammad Ali