Airlines had raised concern saying that the new rules force them to cancel up to 20% of flights which will inflate air fares during the peak summer travel season. Fares are already higher, according to online travel portals as almost 20% of the fleet of Indian airlines are grounded due to engine issues and financial crunch. Among the primary changes, the new rules rewrite the definition of night period, extending it by an hour from 12 AM-5 AM to 12 AM- 6AM.