Due to an unforseen medical exp[ense ,I need to change the date for the state tax payment to next month. I had set it to April 18th , but will not be able to meet tht arr

You will need to contact your state's Department of Revenue to talk to them about changing the payment. 

You didn't mention what state you filed, so I'm including information that lists each state.  Click on your state and you will be taken to your Department of Revenue's contact information.

https://ttlc.intuit.com/replies/3302452