If you look attentively at the output you'll see quite all equinox and solstice in the same output:
% faketime '20 Jun 2019' calendar ... Jun 20* Весеннее равноденствие (Summer Equinox) ... Jun 21* Зимнее солнцестояние (Winter Solstice) Jun 21* Летнее солнцестояние (Summer Solstice) ... Jun 21* Summer Solstice ... It's not just a translation error that thought to fix easily. -- sergio.
