Section 77(9)(iii) in West Bengal Municipal (Employees' Service) Rules, 2010
(iii)Leave for reasons of private affairs except casual leave must be applied for and got approved before it is availed of. Member of the teaching and non-teaching staff before finalizing their private engagement should previously ascertain from the authority concerned as far as practicable whether the leave asked for is likely to be granted provided that in exceptional case of emergency nature in which it was not possible on the part of the staff concerned to apply for the leave and got it sanctioned before proceeding on leave, formal leave application fully stating the facts and circumstances necessitating such leave should be submitted to the authority concerned at the earliest possible opportunity.