I am interested to trade using seasonal charts, can I use the seasonal entry and exit date to trade spot forex ?

The spot market or cash market is a public financial market, in which financial instruments or commodities are traded for immediate delivery.
It contrasts with a futures market in which delivery is due at a later date.

Although all MRCI research is based on US futures prices, I see no reason that one cannot use those
strategies as a guide for trading spot forex.  There will be some differences, of course --- overnight
trading versus 24/7; discounts and premiums in deferred futures. but currencies in the two markets
should move generally together.  CME futures prices are derived directly from spot forex movement

The individual trader has the luxury and responsibility to decide for himself not only whether to assume a position but also when.