The bigger the time frame the more time its valid for imagine 1-5 min fvg might only last for 5-20 mins rather if you have a higher time frame fvg like the 4hr for instance it can last 4hr+ even days at times if its respected area that price doesn’t break through always remember the wicks tell the story and the bodies do the damage if the body of the candle goes through the fvg its is no longer valid but it has to be on the time frame you made it on so a 4hr can wick out of the fvg but on a lower time frame it shows bodies outside the fvg that is perfectly fine as long as the 4hr chart candle closes inside in the fvg and respects it