How Long Is the Overlap in Each Season?

[Fairman]

How Long Is the Overlap in Each Season?

Scenario: using sessions defined as 8 a.m. to 5 p.m. in each city's local time, compute the London and New York overlap in three situations, and express it for a trader at UTC plus 1.

Winter, both on standard time. London is UTC, so 08:00 to 17:00 UTC. New York is UTC minus 5, so 13:00 to 22:00 UTC. Overlap: 13:00 to 17:00 UTC, four hours. For UTC plus 1: 14:00 to 18:00.

Summer, both on daylight time. London is UTC plus 1, so 07:00 to 16:00 UTC. New York is UTC minus 4, so 12:00 to 21:00 UTC. Overlap: 12:00 to 16:00 UTC, four hours. For UTC plus 1: 13:00 to 17:00.

The in-between weeks, with the United States on daylight time and London still on standard time. London is 08:00 to 17:00 UTC. New York is 12:00 to 21:00 UTC. Overlap: 12:00 to 17:00 UTC, five hours. For UTC plus 1: 13:00 to 18:00.

So the overlap is four hours most of the year and five hours for a few weeks.

What does it mean? A strategy whose active window is the first two hours of the overlap should shift by an hour twice a year in local terms, while staying fixed in UTC terms.

Check how your own routine references time. If you use local time, you may be an hour off for several weeks.

Exercise: compute the overlap in your own time zone for each season.