Ages, I'm not really sure when I started, sometime this year. I was gone all of this summer, so that took 3 months out of doing temple.
Good luck, it is so worth it in the end. I bought both giftboxes though, so I'll be starting again for another pet soon. You should definitely consider buying the one that cuts the time in half, I don't think I would have ever finished if I had to wait 48 hours in between.