I just saw this sign:
I typed “aqui há poupança dia sim dia sim” into Google Translate (notoriously unreliable) and it says:
There is money saving here every other day.
But “dia sim dia sim” on its own does not translate to “every other day”.
So what exactly is going on here? (Other than Google being unreliable again)
I’d guess that since it’s an advertisement, that normal rules don’t apply 
That is, grammar is not really applicable and that it means something like “There are savings every day… every day!!!”
but this is just a (educated?) guess.
I think this is a play on words. If I’m not mistaken, “dia sim, dia não” is a common expression that means “every other day”.
So here, they are saying “dia sim, dia SIM”, as a mildly unexpected twist, to mean that every single day, there are savings.
ps. if anyone from Pingo Doce wants to get in touch about compensating us for this free unsolicited promotion… cerveja and gelado are among our many forms of preferred payment 
ps. cool idea posting advertisements and signs as a way for us to nerd out on the language! Keep 'em coming
Oh, Linguee got it wrong, then. Joel’s explanation is absolutely correct
Boo yeah, 10 pontos para o canadiano!
