How did the weather king find the date of the previous year?

By querying the historical weather since 20 1 1:

Step 1: Enter the place name, click Search, and the weather forecast for 15 comes out.

15 There is "Historical Weather" (lower right corner) under the last day of weather forecast, click to enter.

In the upper right corner of the last month's historical weather, modify the year and month, and query the historical weather from 20 1 1 to the present.