Counting down to the four season starts
The seasons here follow the East Asian solar terms: Start of Spring (Lichun, around Feb 4), Start of Summer (Lixia, around May 5), Start of Autumn (Liqiu, around Aug 7) and Start of Winter (Lidong, around Nov 7). These are not the astronomical seasons used in the US, where spring begins at the March equinox (around March 20) and each season starts roughly six weeks later than its solar-term counterpart. Enter the four dates that open spring, summer, autumn and winter along with the day you are counting from, and the table returns the countdown to each one. The stretch your counting day falls inside is named, with its full length, the days gone since it began and the days left until it ends, so you can see how far through a season you are. Adding next year's spring date closes the loop and gives the winter stretch a length too.
No table of dates is built in, because each of these solar terms is fixed by the sun's position along the ecliptic and therefore lands on a slightly different date every year. A hard-coded list would be a day out in some years. So the dates come from the almanac you are reading, and the tool only checks that the four arrive in calendar order. Dates are assembled from UTC components, so the answer does not drift with a device setting. (As of October 2026)
Counting down to a single solar term, or measuring the gaps across all twenty-four of them, is not covered here. Customs and the history behind the terms are left out as well, and a term already past is reported only as the number of days since.
Frequently asked questions
These solar terms are set by the sun's position along the ecliptic, so the dates move every year. A fixed table would be wrong in some years, so the current year's values are taken from you.
No. Leave it empty and the count stops at winter, with the stretch length marked as not entered. Fill it in and winter through to the next spring becomes one measured stretch.
As the number of days since. No negative numbers appear in the countdown column, and a term landing on the counting day itself reads as today.