I was trying to make an appointment with a friend of mine. She asked me to meet up on Wed and I said I will let you know. The day after I texted her: ' ok, it's Wed'. But then I thought I should have said; 'Wed, it is'. Am I right? What is the difference between these two sentences in this context?
Thank you in advance.
I find "OK, it's Wednesday" rather unnatural. If, as in your example, you have been discussing which day to meet and you eventually settle on Wednesday, then we would say "OK, Wednesday it is".
Note that we never say "Wed" as a contraction of Wednesday. You'll see it in writing, but in spoken English we always use the full word, so your post should have had the full word in each quote.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.