Futures rollover

have buyed a future of July series
When I rollover future e.g. from July to Aug series. Do I have to do the sell of alJuy series and buy of Aug series future on same day. ? If it is same day then do I need to sell and buy it immediately on same day, is there a specific time interval within that I have to sell and buy?

That’s what rollover means. When you do it, that;s your choice.

I have buyed a future of July series
When I rollover future e.g. from July to Aug series. Do I have to do the sell of July series and buy of Aug series future on same day. ?

do I need to sell and buy it immediately on same day, is there a specific time interval within that I have to sell and buy ?

No time limit for that gap. It’s all up to you.

Thanks for reply