Abstract: A timekeeping instrument is disclosed which is suitable for teaching a new system of timekeeping, namely, decimal time. By decimal time is meant the division of a day into decimal components rather than the conventional division of the day into hours, minutes and seconds. The teaching instrument disclosed has a single hand which corresponds to the hour hand of a conventional clock and the dial or face of the instrument bears indicia of the normal hourly divisions, that is, the twenty-four hours in a day. The face of the teaching instrument also bears indicia of the decimal divisions of the day. The face may also be provided with a digital display which presents a readout in decimal form of the precise time of day, and the day of the year. Another timekeeping instrument is disclosed which is suitable for timekeeping in decimal time. The instrument disclosed has a single hand and a dial or face having circumferentially disposed decimal divisions.