How to check if the market is closed in MT4
QuoteClient qc = new QuoteClient(500414730, "jjm4cjy", "mt4-demo.roboforex.com", 443);
ConSessions sessions = qc.GetSymbolInfo("EURUSD").Ex.sessions;
"sessions" in this case ConSessions array for each day of week from Sunday,
Each array element contains information about quote and trade session, like open time and close time.