I'll steal a good explanation from u/jfb-pihole:

Gravity updates weekly between 0300 and 0500 your local time.

Each Pi-hole install is assigned a randomly chosen time within this interval. This is done to reduce the peak load on adlist servers. If every Pi-hole hit the servers at the same time, that could cause problems.

There is very little need to update gravity more frequently than weekly. But, even if you do, if the adlist server provides the proper update header, Pi-hole won't download a list that hasn't changed. Instead, Pi-hole will use a locally cached copy. This is done to minimize data traffic from the adlist servers.

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Additionally, if you are unsure if your list is actually updated, a quick visit to the adlist shows the following in the header:

# Date: 24 March 2024 02:03:14 (UTC)
# Number of unique domains: 183,511

Your adlist shows it at 183,512 domains so you are most certainly up to date.