I wish there was a straightforward weekly release schedule for 'Black Clover', but anyone following it knows it's been a bit messy. The official translation on Viz Media's Shonen Jump platform typically updates when a new chapter drops in Japan, which is supposed to be weekly as part of Shueisha's Weekly Shonen Jump magazine. However, the series has had numerous hiatuses over the years due to the author, Yuki Tabata's, health, so you can get a regular weekly run for a few months, then a break announcement pops up. The Shonen Jump app is pretty reliable for sending a push notification when a new chapter is live.
For someone trying to plan a reading session, I'd honestly suggest checking the unofficial scanlation communities or fan subreddits for more immediate update chatter, even though I know we're supposed to support the official release. Those groups often have the raw scans translated and up within a day or two of the Japanese release, sometimes faster than the official English version if there's a holiday or delay. The fan discussions are where you'll hear the real-time grumbling or relief about a chapter dropping, which feels more current than just waiting on the app. It's become a habit of mine to skim those threads first thing Sunday night, just to see if the chapter is out yet, because the official schedule can feel a bit opaque if you're not tracking the Japanese magazine's publication calendar.
All that said, the recent pattern seems to be bursts of chapters followed by a short break, which is becoming more common in Jump for artist wellbeing. I'd set expectations at maybe 3-4 chapters a month on average, rather than a strict four-per-month. The story's in its final arc, so the pace feels urgent, but the release schedule hasn't really matched that lately.