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

Long Interval Milliseconds (ms)

Required number input.

Short Interval Milliseconds (ms)

Required number input.

Timegrapher beat error as half the absolute difference between alternating long and short beat intervals. 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]

Beat Error Milliseconds (ms)

The resulting beat error milliseconds 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.

• Moonphase Correction Days

  Years until an absolute one-day lunar-phase display error from a nonzero drift measured in lunar days per year.

• Chrono Elapsed From Steps

  Elapsed stopwatch time in seconds from beat-counted steps at a known beats-per-hour rate.

• Dual Time Difference

  Shortest signed hour difference from a first 24-hour clock reading to a second reading, in [-12,12).