A trigger signal provided via a pulse-per-second input port of a network interface controller is detected. In response to the trigger signal, an internal hardware clock value of the network interface controller is recorded. The recorded internal hardware clock value is reported, wherein the reported internal hardware clock value is reported for use in determining a timing error of the network interface controller based at least in part on a comparison with a time value of another device that also received the trigger signal.

An electronic timepiece prevents the internal time from shifting because time information for correcting the internal time cannot be received. The electronic timepiece includes: a timekeeper; a receiver; an operating device; an automatic reception controller; a time adjuster; and a reception setter configured to selectively set a first automatic reception prohibition mode that prohibits operation of the automatic reception controller and is cancelled by a single operation of the operating device, and a second automatic reception prohibition mode that prohibits operation of the automatic reception controller and is cancelled by a specific operation of the operating device that is different from the operation that cancels the first automatic reception prohibition mode.

A frequency deviation change rate computation unit (204) computes a frequency deviation change rate being a change rate per unit time of a frequency deviation between a clock frequency of a synchronization reference device serving as a reference of time synchronization and a clock frequency of a time synchronization device which performs time synchronization with the synchronization reference device. A time correction amount computation unit (205) computes a first correction amount corresponding to a static frequency deviation between the clock frequency of the synchronization reference device and the clock frequency of the time synchronization device, performs time integration of the frequency deviation change rate to compute a second correction amount corresponding to temporal transition of the frequency deviation between the clock frequency of the synchronization reference device and the clock frequency of the time synchronization device, and computes a time correction amount for correcting a time of the time synchronization device with using the first correction amount and the second correction amount. A time correction unit (206) corrects the time of the time synchronization device with using the time correction amount.

[Problem] To determine a time difference between clocks which, for example, are placed far apart from each other with high accuracy at low cost. [Solution] In a time comparison system 20, an intermediate station 21 disperses a single optical signal 21c in the spatial region using the optical complex amplitude modulation to simultaneously transmit the optical signal 21c to a plurality of comparative stations 22 and 23 apart from each other. The intermediate station 21 transmits the optical signal 21c while changing the transmission angle using phase modulation, performs intensity scanning for the reflected light c1 of the optical signal 21c, and detects the peak intensity to determine the directions of the comparative stations 22 and 23. The reflected light c1 of the optical signal 21c transmitted to the comparative stations 22 and 23 of which the direction have been determined, is detected to determine a round-trip propagation delay time between the intermediate station 21 and each of the comparative stations 22 and 23. The difference calculation unit 25 calculates a sum of time difference between each of times to and tb associated with the comparative stations 22 and 23 and the time tc associated with the intermediate station 21, and the determined propagation delay time to determine time information of each of the comparative stations 22 and 23. Based on the result of subtracting, from the time information of the comparative stations 22, the time information of the comparative stations 23, the time difference between the comparative stations 22 and 23 is determined.

[Problem] To determine a time difference between clocks which, for example, are placed far apart from each other with high accuracy at low cost. [Solution] In a time comparison system 20, an intermediate station 21 disperses a single optical signal 21c in the spatial region using the optical complex amplitude modulation to simultaneously transmit the optical signal 21c to a plurality of comparative stations 22 and 23 apart from each other. The intermediate station 21 transmits the optical signal 21c while changing the transmission angle using phase modulation, performs intensity scanning for the reflected light c1 of the optical signal 21c, and detects the peak intensity to determine the directions of the comparative stations 22 and 23. The reflected light c1 of the optical signal 21c transmitted to the comparative stations 22 and 23 of which the direction have been determined, is detected to determine a round-trip propagation delay time between the intermediate station 21 and each of the comparative stations 22 and 23. The difference calculation unit 25 calculates a sum of time difference between each of times to and tb associated with the comparative stations 22 and 23 and the time tc associated with the intermediate station 21, and the determined propagation delay time to determine time information of each of the comparative stations 22 and 23. Based on the result of subtracting, from the time information of the comparative stations 22, the time information of the comparative stations 23, the time difference between the comparative stations 22 and 23 is determined.

A time keeping apparatus includes a first region and a second region, the first and second regions are separated by a border. The first region includes a array of minutes indicators, each indicator represents at least 1 minute, and the second region includes a array of stacked hour indicators, each hour indicator representing 1 hour. Each stacked indicator is separated from an abutting stacked indicator.

A time keeping apparatus includes a first region and a second region, the first and second regions are separated by a border. The first region includes a array of minutes indicators, each indicator represents at least 1 minute, and the second region includes a array of stacked hour indicators, each hour indicator representing 1 hour. Each stacked indicator is separated from an abutting stacked indicator.

A method, device, computer equipment and storage medium for GNSS time synchronization are disclosed. The method includes: receiving data packet of NMEA protocol, reading a valid UTC time from data packet of NMEA protocol, and storing the read valid UTC time in a time synchronization controller; receiving PPS signal, capturing a local time output by local clock when PPS signal is generated, and storing the local time in the time synchronization controller; reading a last local time stored before the current local time and reading the stored latest UTC time as a UTC time corresponding to the last local time when the time synchronization controller receives the current local time; and determining, by the time synchronization controller, a local time correction amount according to the last local time and the UTC time corresponding to the last local time, and correcting the local clock according to the local time correction amount.

One embodiment provides a method, including: monitoring, using an accelerometer integrated with an information handling device, gravitational acceleration experienced by the information handling device; identifying, based on the monitoring, a change in the gravitational acceleration from a first gravitational acceleration metric to a second gravitational acceleration metric; and adjusting, responsive to the identifying, a time-keeping standard referenced by the information handling device based on the second gravitational acceleration metric. Other aspects are described and claimed.

One embodiment provides a method, including: monitoring, using an accelerometer integrated with an information handling device, gravitational acceleration experienced by the information handling device; identifying, based on the monitoring, a change in the gravitational acceleration from a first gravitational acceleration metric to a second gravitational acceleration metric; and adjusting, responsive to the identifying, a time-keeping standard referenced by the information handling device based on the second gravitational acceleration metric. Other aspects are described and claimed.