When the Tatkal Window Opens, and Why the Minute Matters
Tatkal booking on IRCTC opens at 10:00 AM for AC classes (1A, 2A, 3A, CC, EC) and at 11:00 AM for non-AC classes (SL, FC, 2S), one day before the date of journey, not counting the day of travel itself. So for a train departing on a Thursday, AC Tatkal opens Wednesday at 10:00 AM sharp.