Started paying alimony Dec 2017, filed married 2017 so I couldn't claim those 4 weeks of alimony. Divorce final in Apr 2018. Can the 4 weeks be claimed in 2018?

I know I can claim all the alimony I paid in 2018 on my 2018 taxes but what about the 4 weeks I had to pay alimony in 2017 but couldn't claim it because we files a married jointly return for that year.