[Sundae]

I work with someone who regularly tells customers to "enjoy the rest of your day"
She is sincere and sweet, but given that I only ever work with her in the morning, it sounds slightly sinister to me.

I think she probably heard someone say it and took it on board as a way of saying "have a nice day" without actually saying that.
It's just to me, picky picky me, it's only really appropriate at the end of the day. And if you just discovered it's someone's birthday or something.

I settle for just saying thank you to customers unless I've had a proper exchange with them. In which case I might hope they enjoy what they're trying, or have a good party etc etc.
While over-using the word lovely of course. Deliberately left that out until now. I'm trying to wean myself off it. It's become a verbal tick, like grim used to be.
Still, that's a positive progression, right?