I am trying to calculate a momentum oscillator for the EUR/USD pair and am confused. A formula I read referenced the sum of previous up days. What is a "day" considered in Forex?
The forex week starts on Monday 7am Wellington time when the Kiwi value date rolls. It ends on Friday 5pm New York. Within that each currency has its own “cut off” time when the value date rolls. The cut off depends on the time zone and liquidity in the currency managed by the dealers who make its market. The convention for an FX day “cut off” for a given currency is not only up to the FX dealers who trade it, but also the money market interest rate traders, as to applying interest on deposits and loans in the currency. Plus it’s up to the central bank. Probably all 3.