Upvote:1
My Arabic is minimal and that scan is pretty blurry, but the word next to Duration looks an awful lot like شهرين shahrayn which indeed means two months. (Fun fact: Arabic numbers have a dual case, which means you don't need to write the number 2 explicitly!)
It's not clear to me if means you get two months from entry, or if it's just repeating the valid-for-entry period. To play it safe, I would assume the latter, meaning you need to plan on leaving by March, or you should be able to extend your visa in Khartoum if need be.
And regarding border officials having discretion to choose how long you can stay, I'm afraid that's pretty much universal.