CME/FX/ICE Sunday OpenDIsplays a background color for CME futures open, forex market open, and ICE US futures open. Since there are varying opening hours for products offered, the opening hours are mainly for currencies, equity indexes, and precious metals.
Currently,
Forex markets open at 1700 EST
CME futures open at 1700 CST
ICE US futures open at 2000 EST
There are alerts for each open.