Looking on the internet deeply has found these results:

either day is the most popular phrase on the web.

either days 154,600 results on the web	either day 1555,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Your father wouldn't forget that day either. I don't do turkey day either. Nothing concrete happened that day either. Your father won't forget that day either. I mean, I can't talk about it either most days. owen had it worse than me. But there wasn't much of either that day, so we got there by early afternoon. Either McCann or Day is really intelligent. Plasma pharmacokinetic profiles were analysed on day 1 and on either day 7 or day 28, by which time plasma concentrations had reached steady state.

either days

154,600 results on the web

either day

1555,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Your father wouldn't forget that day either.
I don't do turkey day either.
Nothing concrete happened that day either.
Your father won't forget that day either.
I mean, I can't talk about it either most days. owen had it worse than me.
But there wasn't much of either that day, so we got there by early afternoon.
Either McCann or Day is really intelligent.
Plasma pharmacokinetic profiles were analysed on day 1 and on either day 7 or day 28, by which time plasma concentrations had reached steady state.