For EST:
0hr - 7pm (-1 day)
3hr- 10pm (-1 day)
6hr - 1am
9hr - 4am
12hr - 7am
15hr - 10am
18hr - 1pm
21hr - 4pm
24hr - 7pm
27hr - 10pm
30hr - 1am (+1 day)
33hr - 4am (+1 day)
36hr - 7am (+1 day)
39hr - 10am (+1 day)
42hr - 1pm (+1 day)
45hr - 4pm (+1 day)
48hr - 7pm (+1 day)
51hr - 10pm (+1 day)
54hr - 1am (+2 days)
57hr - 4am (+2 days)
60hr - 7am (+2 days)
63hr - 10am (+2 days)
66hr - 1pm (+2 days)
69hr - 4pm (+2 days)
72hr - 7pm (+2 days)
75hr - 10pm (+2 days)
78hr - 1am (+3 days)
81hr - 4am (+3 days)
84hr - 7am (+3 days)
87hr - 10am (+3 days)
90hr - 1pm (+3 days)
93hr - 4pm (+3 days)
96hr - 7pm (+3 days)
You get the idea.
