On Sunday High tide is 10:53am and
Low tide 17:22pm thinking of spending 1 or 2 hours there. What time should I go to Hilbre island and come back to main land?

It is recommended to leave for Hilbre no earlier than three hours after high tide. This will give you plenty of time on the island. It is also recommended to leave the island three hours before the next high tide. On this advice you can plan your journey times very easily.
I walk this route a couple of times a year and love sitting on the island with a few butties and a drink, taking in the views. I would also recommend waterproof boots.

https://www.greatbritishlife.co.uk/...alk-west-kirby-and-hilbre-island-7198056