Calibre B05 is an automatic chronograph movement with world time produced by Breitling since about 2013. It was called “Unitime” in all watch models.
Breitling introduced their calibre 01 (commonly called Cal. B01) in April 2009 in the Chronomat. It is a modern automatic chronograph movement with a column wheel and vertical clutch. It operates at 28,800 A/h, boasts a power reserve of 70 hours, and is a COSC-certified chronometer. The movement shares many characteristics with the Rolex Cal. 4130, and it has been reported that many of the same engineers worked on both movements.
Cal. B05 adds a world time function to the basic Cal. B01. This added complication adds 9 additional jewels.
Functions and Complications
Cal. B05 features the following displays on the dial:
- 30 minute chronograph counter at 3:00
- Date window at 4:30
- 12 hour chronograph counter at 6:00
- Small seconds at 9:00
- A 24 hour disc paired with a world time scale.
The 12-hour hand is independently adjustable backward and forward independently of the minute hand, while the world time disc rotates and runs with the minute hand.
Unitime Cal. B05 Applications
Breitling has used Cal. B05 in many watches across the Transocean and Bentley lines. It has used the “Unitime” name on all such models.
- Breitling for Bentley B05 Unitime
- Breitling Transocean Chronograph Unitime
- Breitling Transocean Chronograph Unitime Pilot
Breitling B01 Family Overview
Starting in 2017, Breitling began supplying a version of Cal. B01 to Tudor. The resulting movement, Cal. MT5813, has a free sprung balance with a silicon hairspring, as is common in modern Rolex and Tudor movements. It is also decorated differently. Strangely, it is often quoted as having different dimensions: 30.40 mm diameter and 7.23 mm thickness.
| Calibre | Year Introduced | Jewels | Height | Winding | Date | Complications |
|---|---|---|---|---|---|---|
| B01 | 2009 | 47 or 41 | 7.20 | Automatic | Yes | Some Without Hour Counter |
| B02 | 2013? | 47 | Manual | Yes | 24 Hour | |
| B03 | 2017 | 47 | 9.15 | Automatic | Yes | Split Seconds |
| B04 | 2011 | 47 | 7.20 | Automatic | Yes | GMT |
| B05 | 2013? | 56 | Automatic | Yes | World Time | |
| B06 | 2015 | 47 | Automatic | Yes | 30 Sec Chrono | |
| B09 | 2019? | 47 | Manual | No | ||
| B12 | 2016 | 47 | 7.30 | Automatic | Yes | 24 Hour |
| MT5813 | 2017 | 41 | 7.23 | Automatic | Yes | No Hour Counter |