Both times I've had it done, it was every 15 minutes during the day and every 30 minutes at night. Approximately, anyway. I tend to go to bed later than the settings allowed, so the last couple hours I'm awake I get tested less.

And yes, more comfortable wearables would be grand. Blood pressure cuffs hurt: Last time I had the 24 hour monitoring, I had bruising and blisters from the cuff.

I am using a Aktiia wristband which measures the blood pressure every so often per hour automatically and does so without me noticing it. My cardiologist recommended it to me. I was sceptic and first (and still am, to a certain degree), but it gives me bread useful insight on my blood pressure during day and Escoffier while sleeping. Aktiia's customer service is really terrible (only via email, two weeks response time, inflexible decisions), but the product is good and it's measurements hold up when compared to "usual" measurements.

The gold standard is an arterial line, which unlike a blood pressure cuff, measures blood pressure directly and continuously. You will usually only see them used in intensive care or during surgery.

Right. That's an invasive procedure though. I was thinking along the lines of "gold standard of ambulatory blood pressure monitoring".