Actually this is an excellent topic. Day to day life changes are often neglected by authors.
Perhaps we could have a world with more Chinese influences, making the bridal gowns red, and mourning dress white, like we have white and black respectively.
I could easily see some nation encouraging the citizens to wear traditional clothes for weddings, probably some dictatorship or so.
There could be also, no wedding industry... there was little before XX century, where middle class started to mimic upper classes for that special day. Yes people usually dressed in their best, but buying or renting a wedding dress would never crossed their minds.
Male dresses? Perhaps a world where Scandinavia is more powerful and
búningur and bunad spread across the world? Or perhaps just any other two cultures mixed and clashed for years, stealing from each other... Here is an example of male dress that was result of a mix of Turanian and European influences.
As for clothing is concerned, we have to remember that daily clothing has to be practical. Details can change according to region and fashion, but the necessities behind them remain the same. It has to allow work - ie freedom of movements, protect from minor scrapes and elements, and be relatively easy to wash to wear it another day. Thats why, nurse uniform would most likely be a one colour other than black or crimson, so it would be easy to see that it is stained by blood (and therefore making it unsterile and making washing necessary), and it would be easy to guess that a person in question is a nurse in emergency. The uniforms do not have to be white, and even in OTL there are nurses who do their job in yellow, or blue attire. Likewise a hat is useful in that job, to keep hair from falling into ones eyes, or worse, into patient's open wounds. The hut's cut is not as much relevant, and as you could see it changed a lot OTL.
As for displaying military ranks we had three ways of doing it in modern warfare: shoulder marks, shoulder boards, and collar marks. All of them do their duty, hence it is safe to say that either could "win". If we move POD further back, and keep world at relative peace, we could easily see the millitaries keeping older, more elaborate ways to show the rank and formation.
Like wise jeans could be easily replaced by any other tough fabric capable of resisting the daily toil and dyed by cheap chemicals.
As for bikini - these are leisure clothes, and are shaped more by fashion rather than any practical need. As you could see the swimming suits evolved a lot during last few hundred years, and they could be either or none.