Are there any hours when the following exchanges are closed for trading e.g. during maintenance:

CME
CBOT
NYMEX
COMEX

or are non-trading times contract specific?

I am asking because I am trying to set up automated trading and need to do some updates/maintenance every day when the markets are not trading.

bluefightingcat 

Are there any hours when the following exchanges are closed for trading e.g. during maintenance: CME CBOT NYMEX COMEX or are non-trading times contract specific? I am asking because I am trying to set up automated trading and need to do some updates/maintenance every day when the markets are not trading.

This should help Trading Hours: Futures & Options

All the exchanges you quoted are owned by the CME group.