Here is collection of Soviet post cards for International Women's Day celebrated in USSR as Mother's day.

https://kulturologia.ru/blogs/080315/23587/ https://swalker.org/other/1342-sovetskie-otkrytki-na-8-marta...

You probably meant "celebrated in lieu of Mothers' Day" -- March 8th has always been advertised, as it were, as "women's holiday" in USSR, there were no Mothers' (or Fathers') day per se.

Internally this was precisely Mother's day. As 23rd of February, "defender of the Fatherland Day" was Father's day as all us, men, were liable for military service.

I am for example Lieutenant-reserve of USSR's Strategic Rocket Forces ( https://en.wikipedia.org/wiki/Strategic_Missile_Troops )

I got out of serving by going to a college with Военная кафедра [0], but I think we're saying pretty much the same thing -- USA and rest (or most, anyway) of the Western world has non-political Motrher's and Fatrher's day, completely separate from the International Women's Day (let alone Defender of the Fatherland day, which is obviously USSR-specific), while back in the USSR we had a generic women's/men's holidays tacked onto March 8th and Feb. 23rd respectively.

I don't remember them ever being even positioned as specifically Mother's/Father's day; I am sure that you have also given gifts to your female classmates even in elementary school on March 8th, and received some on Feb. 23rd, even though becoming a parent while in school was an extremely rare occurrence.

[0] For the benefit of those who did not have to deal with it, something similar to ROTC in the US, but available only in some colleges/universities, and mandatory in those where it were available. Instead of being drafted for 2/3 years upon hitting the draft age, you'd receive training there, spend some reasonably short time in the armed forces, and get a reserve officer's rank.