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  • The Observatory joined Rapid Coordinated Universal Time Project

  • Monday, 7th January 2019

The Hong Kong Observatory (HKO) has been contributing to the determination of Coordinated Universal Time (UTC) since 2004 by regularly transmitting data of its Caesium Beam Atomic Clock to the Bureau International des Poids et Mesures (BIPM). The differences between the Hong Kong Standard Time (HKT) and UTC have been computed once a month for clock monitoring and adjustment as appropriate. During the fourth quarter of 2018, the Observatory has also joined the Rapid Coordinated Universal Time (UTCr) Experiment of BIPM. Data transmission is now carried out at an increased frequency of once a day and the interval between successive computations of time departures shortened to a week. This facilitates a more efficient monitoring of the Hong Kong Standard Time.

Figure 1

Note: The Modified Julian Date is a count of days without specifying the year or month. 58119 in Modified Julian Date is equivalent to 1 January 2018 and 58484 is 1 January 2019.