According to the setup, Higgins is currently in Kenya while magnum is still in Hawai'i.
The is issue is though that the time zone difference between Nairobi and Honolulu is 13 hours with Kenya being 13 hours ahead.
This means that while in the summer the sun can be up a bit past 9 pm, in the episode its clearly visible that Higgins to talks to magnum in the early afternoon at most and magnum talks to her in the morning hours, as evidenced by Rick's bar being already open.
On the real world Higgins would be past sunset.
The is issue is though that the time zone difference between Nairobi and Honolulu is 13 hours with Kenya being 13 hours ahead.
This means that while in the summer the sun can be up a bit past 9 pm, in the episode its clearly visible that Higgins to talks to magnum in the early afternoon at most and magnum talks to her in the morning hours, as evidenced by Rick's bar being already open.
On the real world Higgins would be past sunset.