The calendar’s reference time zone

UTC+8

UTC+8 means eight hours ahead of Coordinated Universal Time. The Atlas displays solar-term timestamps in this fixed offset by default. Modern Chinese calendar calculations also use this reference clock to assign new moons and solar terms to calendar dates.

An astronomical event occurs at one instant, but clocks in different time zones can show different dates at that instant. The reference time zone determines the date used to place the event in the calendar. Converting its timestamp for another location changes the clock reading, without changing that reference date.

Midnight and month boundaries

A Chinese lunar month begins on the calendar day containing the astronomical new moon. The new moon is an instant, while the first day is a whole day. Lunar day one starts at midnight at the beginning of the new moon's reference date, even when the conjunction occurs much later that day.

A new moon close to midnight creates a sensitive boundary. A small difference in its calculated time can put it on the adjacent calendar date, shifting the start of the month by a whole day.

The same calendar-day principle matters for principal terms. When a principal term and a new moon occur on the same reference date, that date belongs to the new lunar month, regardless of which event occurs first during its hours. Assigning terms by intervals between the exact conjunction instants can give a different result from assigning them to calendar months.

The 2026 Lichun transition

Lichun, Beginning of Spring, fell at 04:02 on February 4, 2026 in UTC+8. Subtracting eight hours gives 20:02 UTC on February 3. The table expresses the same instant in three fixed offsets, with times given to the minute.

Beginning of Spring remains on February 4 in the Atlas's reference calendar. To express its time for a particular location, use that location's offset on the event date, including any daylight-saving adjustment. An offset such as UTC−8 is fixed, while a location's clocks may change seasonally.

Converting the timestamp is separate from deciding whether a particular almanac or astrological system begins its year at Chinese New Year or at Lichun.

Today and selected dates

The Almanac link opens the Gregorian date on your device. That local date can differ from the date in UTC+8 at the same moment. Solar-term timestamps still retain their stated reference offset.

A permanent date page keeps its written civil date. In the Calendar, browsing another month and selecting another day are separate actions: browsing leaves the selected date in place, while choosing a day changes the selection. These operations choose a record from the same calendar. They do not recalculate lunar months for the reader's location.

Historical time standards

Late Qing and early Republican calendar calculations used Beijing local apparent solar time, which followed the apparent motion of the Sun. Beijing mean solar time, which averages that motion, was used from 1914 through 1928. A standard eight hours ahead of Universal Time was adopted in 1929. UTC was developed later, so “UTC+8” is a modern designation rather than the original name of all these earlier clocks.

Different reference clocks place midnight at different instants. Together with changes in astronomical methods, this can account for a date in an older calendar differing from a modern calculation extended backwards.