H1 petition is approved but I want to delay my stamping so how long can I delay it

H1 petition is approved on 13th Jan 2017. Due to some family issues I have to delay my travel to US. How long can I delay my H1 stamping. And also please let know if my H1 stamping is approved and H1 is valid for 1 year and I choose to travel next then what will options.