Plz See Below Para. It will give you brief idea
As per Standing Order Central Rules 1946 Sec.10. Casual leave.--A workman may be granted casual leave of absence with or without pay not exceeding 10 days in the aggregate in a calendar year. Such leave shall not be for more than three days at a time except in case of sickness. Such leave is intended to meet special circumstances which cannot be foreseen. Ordinarily, the previous permission of the head of the department in the establishment shall be obtained before such leave is taken, but when
this is not possible, the head of the department shall, as soon as may be practicable, be informed in writing of the
absence from and of the probable duration of such absence.
1st August 2012 From India, New Delhi