I want to book a table for three between 20:30 - 21:00
Я хотел бы заказать столик для троих между полдевятого и девятью.

This language is so annoying when it refers to numbers, dates, time, decimals etc.
When contemporary Greeks failed to use the complexity of some aspects of the ancient Greek language they have created a modern simplified version called: Modern Greek.
I think you should do the same if you want more foreigners to start learning Russian.