Valid from date on cert off by 1 hour

At least on the staging server, when I am issued a cert, the date is 1 hour behind. I issued it at 5:23 PM GMT but when I check the field in the browser it shows 4:23 PM GMT. Is there a reason for this?

https://sitetemplate.org.d11.amst.com/

Let’s Encrypt backdates certificates by one hour from the time of issuance to avoid issues with clock skew.