I've never been a huge fan of date windows, probably because they tend to disturb the aesthetic of a nicely-proportioned, symmetrical dial. There are a few exceptions, however. One of them is this nice Poljot 2414, found with a number of dial variations:
My favorite iteration is the one with the cute little Sputnik Poljot logo. As I understand, this insignia was an early adoption of the Poljot brand name, probably used sometime in the early 1960s. Some dials even have the "KL 1" insignia, the likes of which I've only otherwise seen on Strelas -- though I'm sure this designation appears on a number of other dials from the early '60s.
(The date magnifier bubble is on the inside of the plastic, meaning the surface of the crystal is completely smooth)
All four watches pictured above are very similar in design, yet no two are the same. Variations include case material (gold-plated vs. chrome-plated), hour markers (batons vs. numerals), logo (English vs. Cyrillic), and class designation ("first class" vs. no marking). But overall, the watches are highly similar. This is the same when viewed on the reverse. The screw-down back and conical crown match those of Kirovskies.
When you expose the movements, however, things get very interesting. No two movements are alike, and some are unlike any movements I've ever seen before. Notice the two watches on the left have standard 1MWF movements: one from post-1963 with the pentagon logo, and one from pre-1963 with the diamond logo. But notice the two movements on the right. What's going on here? Surely no mistake, as there are two movements exhibiting some of the same strange features. But even these two are not the same. Both are labeled "Bienna 17", while one says "Jewels" and the other is inscribed "Uewels". I've seen some pretty strange things during my short tenure as a Soviet watch collector, but this is truly bizarre. I've found more evidence of this movement (see here and here and here), so it's certainly no coincidence. But I'm quite perplexed as to the origins of this unusual inscription.
The two "Bienna" movements are further differentiated by the inscriptions beneath the balance. The first movement, as usual, shows a serial number as well as "2414", indicating the movement caliber.
The second movement, however, has no such markings. Instead, it has only a small triangle with "B 114" written inside.