I’ve wondered this myself, but at a guess, I’d assume that they’d attach a 1hr window to the time change. So to use your example:
1400h egg price is set to £3.00
1445h you pick eggs off the shelf
1500h egg price set to £3.05
1515h Jane picks eggs off the shelf at £3.05
1530h you get to the till and pay £3.00
1535h Alice gets to the till and pays £3.05
Basically, so long as you’re in and out within an hour, any price rises (not drops, likely) within that hour don’t apply to you.
Alternatively, there’s a continued push to use the self scanning guns, those things you take with you in your cart as you shop. These could track the time of purchase and thus give you up-to-the-second pricing. Of course this only works if everyone has to use those things. I’m sure that’s next.
I’ve wondered this myself, but at a guess, I’d assume that they’d attach a 1hr window to the time change. So to use your example:
Basically, so long as you’re in and out within an hour, any price rises (not drops, likely) within that hour don’t apply to you.
Alternatively, there’s a continued push to use the self scanning guns, those things you take with you in your cart as you shop. These could track the time of purchase and thus give you up-to-the-second pricing. Of course this only works if everyone has to use those things. I’m sure that’s next.