The sentence 'opening hours are subject to change' is correct and usable in written English. It can be used in any situation where the opening hours of a business or other service may change, and the author wants to provide notice of this. For example, you might include this sentence on your website or in a newsletter to let customers know that opening hours are subject to change.
Call before going; store hours are subject to change.
Hours are subject to change.
Plans are subject to change.
Performances are subject to change.
Shows are subject to change.
SEPTEMBER All dates are subject to change.
As always, dates are subject to change.
Awesome tool! I started using it one year ago and I never had to look for another app
Ha Thuy Vy
MA of Applied Linguistic, Maquarie University, Australia