This is indeed not that easy. The information you were looking for is available for instance here: City of Zurich or consumer show. As those are in German, let me summarise the most important rules:
You need a parking disc. The parking disc allows you to park for the following durations:
- You can park for one hour Mo-Sa from 08:00-11:30 and from 13:30-18:00
- If you reach between 11:30 and 13:30 you can stay until 14:30
- If you reach after 18:00 you can stay until 08:00 the following day
- There are no restrictions on Sundays and public holidays unless there is a sign indicating so
Note that there are sometimes signs indicating a different duration (hence the confusing information you found). This also only applies to blue zones, there are other zones which also require the parking disc, those will always have a sign indicating how long you can stay.
Now you always set the dial of the disc on the next half hour (it only comes with half-hourly markings). So effectively, you can stay up to 1.5 hours. Let's say you reach at 09:01, you have to put the time 09:30 and can stay until 10:30. If you arrive at 09:29, you still can only stay until 10:30. (This is the actual rule and not a way to cheat the system).
If you go back to the car and reset the disc to extend your parking time without moving the car you might get fined.
The parking discs are usually issued by the town and if your car doesn't already come with one, you can get them at petrol stations or post offices. You can use the same disc everywhere in Switzerland, but foreign ones are not valid. Sometimes all the information I just wrote down is actually printed on the back of the disc.