I have seen & heard many time phrases like "Wait another 2 days". How is it possible? Another = an other = one other (singular) and here we have 2 days (plural). Is it an accepted "mistake"?
We frequently use "another" before a plural noun.
May I have another three glasses of wine, please?
I have to wait another four months to find out if I passed my exam!
Another twelve people turned up late to the meeting.
Think of it as "a further".
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.