Okay, so I've been looking and I can't find one, the two month calendars I see require you to write out the whole month a second time which is stupid as eating shit.
The concept isn't difficult, you have January and February showing, then at the start of Feb you fiddle with it and scroll it so that February and March are showing. No writing out the whole month again.
Single month wall calendars have always seemed stupid as when it is late in the current month, you have no quick glance option for next week / month.
If I can't find one, I'll buy two hang them both up and swap them physically over each month, only filling out one month each time.
I'm a bit confused. So on one page you want Jan/Feb. Then on the next page you want Mar/Apr?
Or do you want a big January, with Dec and Feb in a small window at the bottom?