Thanks for confirming, was the spread i was making mention of, not the price.
The 17H00 prints on the T&S that can be seen, i understand that the professional outfits get to trade outside hours but that then is also the MM like arrangement squaring his books for the day is it?
Well there are generally not market makers for most stocks. They would usually be there for IPOs, demergers etc. and then only for a limited time. And ETFs have market makers as mentioned. That's why I mentioned "in limited cases".
In any case the presence of market makers would not widen the spread. Usually their prices would be well outside the spread in any case just to ensure that there is liquidity if necessary. That was my point on their price. They are obligated to provide the liquidity but usually they don't actually want to trade.
And yeah, as rietrot mentioned, buy or sell orders can remain open indefinitely depending on how they are placed. The usual 3 options are "good until close" (or good for the day), "good until [date]" and "good until filled" (i.e. open until it trades) but technically you could put in an order that is good for 30 minutes if you wanted.