All breaks at Warner properties up to 26 July have been postponed; guests should not travel to their destination.
From 27 July, all breaks are scheduled to go ahead as planned, subject to further UK government and Welsh Assembly guidance.
Warner will be publishing updates as it gets them on its website and across its social channels.
"This date has been chosen to allow us to fully implement all our new measures for your health, safety and enjoyment," said Warner.
"It gives us the time to restock our larders, fridges and bars, rearrange furniture for social distancing, and get fresh linen on the beds.
"Importantly, it’ll ensure our teams are well-equipped and trained, ready to welcome everyone back in the safest possible way."
