Section 8(2)(b) in The Madras Port Petroleum Rules, 1963
(b)In the case of interruption to pumping after sunset due to any reasons, other than those stated in Cl. (a) above, the Deputy Port Conservator may, at his discretion, grant special permission to re-commence pumping even during the night time. Discharge of dangerous petroleum interrupted or suspended after sunset, shall on no account, be re-commenced until after sunrise, without the permission of the Deputy Port Conservator.