A list of the nightmare times and other in-game times depending on the server time. (in 15 minute intervals or 3 hours in-game time).
Server Time (PST)____In-Game Time____(NM = Nightmare Time)
24:00-24:15 = 11:00-14:00 (midnight to 1am)
24:15-24:30 = 14:00-17:00
24:30-24:45 = 17:00-20:00
24:45-01:00 = 20:00-23:00
01:00-01:15 = 23:00-2:00 = NM (1am to 2am)
01:15-01:30 = 02:00-05:00
01:30-01:45 = 05:00-08:00
01:45-02:00 = 08:00-11:00
02:00-02:15 = 11:00-14:00 (2am to 3am)
02:15-02:30 = 14:00-17:00
02:30-02:45 = 17:00-20:00
02:45-03:00 = 20:00-23:00
03:00-03:15 = 23:00-2:00 = NM (3am to 4am)
03:15-03:30 = 02:00-05:00
03:30-03:45 = 05:00-08:00
03:45-04:00 = 08:00-11:00
04:00-04:15 = 11:00-14:00 (4am to 5am)
04:15-04:30 = 14:00-17:00
04:30-04:45 = 17:00-20:00
04:45-05:00 = 20:00-23:00
05:00-05:15 = 23:00-2:00 = NM (5am to 6am)
05:15-05:30 = 02:00-05:00
05:30-05:45 = 05:00-08:00
05:45-06:00 = 08:00-11:00
06:00-06:15 = 11:00-14:00 (6am to 7am)
06:15-06:30 = 14:00-17:00
06:30-06:45 = 17:00-20:00
06:45-07:00 = 20:00-23:00
07:00-07:15 = 23:00-2:00 = NM (7am to 8am)
07:15-07:30 = 02:00-05:00
07:30-07:45 = 05:00-08:00
07:45-08:00 = 08:00-11:00
08:00-08:15 = 11:00-14:00 (8am to 9am)
08:15-08:30 = 14:00-17:00
08:30-08:45 = 17:00-20:00
08:45-09:00 = 20:00-23:00
09:00-09:15 = 23:00-2:00 = NM (9am to 10am)
09:15-09:30 = 02:00-05:00
09:30-09:45 = 05:00-08:00
09:45-10:00 = 08:00-11:00
10:00-10:15 = 11:00-14:00 (10am to 11am)
10:15-10:30 = 14:00-17:00
10:30-10:45 = 17:00-20:00
10:45-11:00 = 20:00-23:00
11:00-11:15 = 23:00-2:00 = NM (11am to noon)
11:15-11:30 = 02:00-05:00
11:30-11:45 = 05:00-08:00
11:45-12:00 = 08:00-11:00
12:00-12:15 = 11:00-14:00 (noon to 1pm)
12:15-12:30 = 14:00-17:00
12:30-12:45 = 17:00-20:00
12:45-13:00 = 20:00-23:00
13:00-13:15 = 23:00-2:00 = NM (1pm to 2pm)
13:15-13:30 = 02:00-05:00
13:30-13:45 = 05:00-08:00
13:45-14:00 = 08:00-11:00
14:00-14:15 = 11:00-14:00 (2pm to 3pm)
14:15-14:30 = 14:00-17:00
14:30-14:45 = 17:00-20:00
14:45-15:00 = 20:00-23:00
15:00-15:15 = 23:00-2:00 = NM (3pm to 4pm)
15:15-15:30 = 02:00-05:00
15:30-15:45 = 05:00-08:00
15:45-16:00 = 08:00-11:00
16:00-16:15 = 11:00-14:00 (4pm to 5pm)
16:15-16:30 = 14:00-17:00
16:30-16:45 = 17:00-20:00
16:45-17:00 = 20:00-23:00
17:00-17:15 = 23:00-02:00 = NM (5pm to 6pm)
17:15-17:30 = 02:00-05:00
17:30-17:45 = 05:00-08:00
17:45-18:00 = 08:00-11:00
18:00-18:15 = 11:00-14:00 (6pm to 7pm)
18:15-18:30 = 14:00-17:00
18:30-18:45 = 17:00-20:00
18:45-19:00 = 20:00-23:00
19:00-19:15 = 23:00-2:00 = NM (7pm to 8pm)
19:15-19:30 = 02:00-05:00
19:30-19:45 = 05:00-08:00
19:45-20:00 = 08:00-11:00
20:00-20:15 = 11:00-14:00 (8pm to 9pm)
20:15-20:30 = 14:00-17:00
20:30-20:45 = 17:00-20:00
20:45-21:00 = 20:00-23:00
21:00-21:15 = 23:00-2:00 = NM (9pm to 10pm)
21:15-21:30 = 02:00-05:00
21:30-21:45 = 05:00-08:00
21:45-22:00 = 08:00-11:00
22:00-22:15 = 11:00-14:00 (10pm to 11pm)
22:15-22:30 = 14:00-17:00
22:30-22:45 = 17:00-20:00
22:45-23:00 = 20:00-23:00
23:00-23:15 = 23:00-2:00 = NM (11pm to midnight)
23:15-23:30 = 02:00-05:00
23:30-23:45 = 05:00-08:00
23:45-24:00 = 08:00-11:00