Answer depends on your coolant and engine manufacturer.

Green coolant or ethyl glycol 2 years life. Common brands are prestone, total, whiz etc...

Dexcool or orange coolant is supposed to be 5 years or 100,000 kms. Personally, I'll still change every 2 years. Normally found on GM cars. Caltex is the manufacturer. Ford prohibits the use of this coolant on their engines.

Toyota uses red coolant. I forgot idf its HOAT or OAT. Also forgot the reccomended change interval. Parang 2 years din but I may be wrong.

No idea on Honda, Mitsu, German and Korean cars.

Bottom line check your manual.