When you run either a hotels / hoteldetail operations, you will receive the lastUpdate tag. This tag will show when was the last time that hotel had any update on any of the fields returned on content-api. Using this information, you will be able to update hotel content in your database according to the latest change. Bear in mind the format will be YYYY-MM-DD
When requesting information for hotelcode = 16, lastupdate received 1st January 2022
<hotel code="16" web="http://www.hotelcastillosanjorge.com/" S2C="4*" ranking="1" lastUpdate="2022-01-01">