If Jesus Is God, Why Didn’t He Know the Day of His Return?

Questions about why Jesus didn’t know the day of his return if he truly is God, and why it’s important for Jesus to be both fully God and fully man. If Jesus is God, then why didn’t he know the day of his return, and if the answer is that he limited himself, wasn’t it a lie to say that he didn’t know? Why is it important for Jesus Christ to be both fully God and fully man?