。
It's dinnertime.
Literal
Dinner-of time is-[polite-ですよ].
夕食 ('dinner') is the standard, neutral noun for the evening meal — distinct from the homier 夕飯 (やはん/ゆうはん). The pattern [noun]の時間ですよ ('it's [noun]-time, you know') is a common reminder construction, used by parents calling family to the table or by hosts cuing a meal.