At last.!.

there's nothing flat-earthy about different definitions for the same word..
and for some other flavours:
"Ireland uses an ancient Celtic calendar system to determine the seasons, so spring begins on St Brigid's Day on February 1. Some cultures, especially those in South Asia have calendars that divide the year into six seasons, instead of the four that most of us are familiar with.
In Finland and Sweden, the dates of the seasons are not based on the calendar at all, but on temperatures. Here, spring officially begins when the average temperature rises above 0 °C (32 °F). This means that the seasons within each county start and end on different dates, depending on the regions and their climate."
[timeanddate.com]