Use this horology calculation to interpret a stated watch, clock, timing-machine, water-resistance, alarm, or historical respiratory-timing quantity under its defined convention.

Start Degrees (deg)

Required number input.

End Degrees (deg)

Required number input.

Positive angular sweep of a retrograde indicator from start angle to end angle. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Sweep Degrees (deg)

The resulting sweep degrees returned as a number.

• Mechanical-watch amplitude and beat measurements depend on lift angle, position, state of wind, movement condition, instrument setup, and elapsed sampling. ATM markings are test-pressure classifications rather than literal safe diving depths.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Confirm movement specifications and measure in multiple positions and power states; follow the manufacturer's water-resistance guidance and obtain pressure testing after case service.

• Retrograde Return Time

  Average angular return speed in degrees per second from sweep angle and return duration.

• Day Disc Advance Rate

  Day-disc angular advance in degrees per daily step for a specified number of disc positions.

• Week Disc Advance

  Week-disc angular advance in degrees per weekly step for a specified number of positions.