Section 32(e) in West Bengal Municipal (Employees' Service) Rules, 2010
(e)if an employee, while officiating in a post or holding a temporary post on time-scale of pay, is appointed to officiate in a higher post or to hold a higher temporary post, his officiating on temporary service in the higher post shall, if he is re-appointed to the lower post, count for increments in the time-scale applicable to such lower post. The period of officiating service in the higher post, which counts for increments in the lower post, is, however, restricted to the period during which the employee would have officiated in the lower post but for his appointment to the higher post.
