Forex Trading On Saturday:

In reality the market does not close on Saturday. But most, if not all online brokers, freeze their platform that day because usually activity is low and the movers (liquidity providers) like central banks, financial institutions, hedge fund managers are closed too.
You need to understand that online  traders only do electronically what the aboki's do on the street; though because naira is not as liquid as USD/GBP/EUR/AUD/NZD/JPY/CAD, most brokers don't offer naira as a currency pair on their platform.
You know that if you want to exchange dollar on Saturday, aboki's will sell or buy from you.

But i still think it is wrong for them to tell people they can trade on Saturday, unless they know any broker that allows that