I have a Magento 220.127.116.11 installation with timezone GTB. I have the known problem with the catalog price rules which disappear in the level of product view only; i.e. they are visible in product list.
I have read a lot for this problem around the Internet, but I have not found a stable solution. In the past I had solved it by changing the time cron runs Catalog Rules in the below file. Namely, I have setup this to 03:50 in the morning on daily basis:
However, the problem returned back when the Winter Time came.