Incorrect date while saving csv format

Hello,

I am trying to save a csv format of an excel sheet. My sheet has dates from 1 Dec'18 to 31 Jan'19. But when I save the csv file and reopens it, the date gets changed. 1 Dec'18 to 31 Dec'18 is alright but 1 Jan'19 to 31 Jan'19 gets converted to 1 Jan'18 to 31 Jan'18. It automatically changes the year from 2019 to 2018. I have tried changing the system dates from control panel but it does not help. Any suggestions to correct this problem.