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

Utc Hour

Required number input.

Utc Minute

Required number input.

GMT hand angle relative to the 12 o'clock position on a 24-hour dial from UTC hour and minute. 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]

Dial Degrees (deg)

The resulting dial 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.

• World Time Zone Offset

  Local 24-hour clock hour from UTC hour and a signed, possibly fractional, offset in hours; does not determine DST.

• Dual Time Difference

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

• Alarm Set Offset

  Forward minutes from current clock time to an alarm time, wrapping at 24 hours.