You probably can arrange to have the closing date changed, but before you ask bear in mind:
1. Citi closing dates move around depending on the length of the month.
2. They will probably ask you to choose a new "Payment Due Date", rather than a "Statement Closing Date". The Due Date is 25 days after the closing date, which means that if you want a Closing date "around" the end of each month you will need to ask for the Due Date around the 25th.
3. Some dates will be unavailable, such as the 29, 30, and 31, because those do not occur in every month.
4. A change requested today may not take effect immediately Just now, I asked to have a different Citi card Due Date changed from the 8th to the 6th, and the change will be effective on the statement which will close in April and due in May.
If I ask to extend my due date from the 20th to the 25th for example, will this incur any interest or fees since it would be making the grace period 30 days that month? I am on auto pay. Perhaps I should make a manual payment the first month? Not sure how this change affects things.