[Rolex] Frank Muller’s custom Rolex datejust he turned into a Perpetual Calendar.

The story goes that Frank Muller before going on his watchmaking journey decided to make a custom watch for his friend. Who exactly this friend was is a bit of a mystery. Muller started out by taking in a 16238 reference gold datejust at 36mm with the watches base calibre 3135 movement inside.

Muller went to work by “heavily modifying” the movement. He made a date only watch turn into a perpetual calendar, he added a month & leap year indicator, a date register, a moonphase indicator, & a day of the week register to create the first Rolex perpetual calendar.

I don’t think people realize how insanely talented Frank Muller was as a watchmaker to heavily modify a date only watch specially a small 36mm datejust into a full on perpetual calendar. And on top of that it was for a dear friend, not a client customer, just someone he wanted to give an appreciative thanks to. I think as amazing as a watchmaker he was, he was an even better friend. And for those wondering now who owns this watch? Well that would be none other than Artist & Rapper Jay Z.