Awesome. I'm jealous. Those Piper Glens are super nice.
My tub heated up in time for an evening soak. It was delivered and powered up by 11AM. Water temp started in the low 60s. I want to say it climbed about 6 degrees an hour (1 degree every 10 minutes).
It's a bit warmer now, so yours might not take quite as long today and your starting water temp might be a bit higher as well.