In Germany, my kid had one or two weeks of slowly getting used to the kindergarten. We were a bit pushing for a faster track and the kid had a blast from day 1 (they were 4 months when they started on going 5 days a week, 6h/day). We were encouraged to stay with the kid only the first day or two.

France was even quicker: the whole process lasted 3 days (a visit of an hour with parent, 3 hours, 4 hours with nap, full day) at 18 months.

I heard from a friend in Austria that the process took a full month and a half! And it was considered quick. My friend was going out of his mind juggling everything.

Drop child off at daycare.

Child may cry. Child may be sad for a short time. Child is not in any actual danger and will get over it. Repeat the next day. Next day, child cries less. Child is sad for shorter amount of time. Child is still not in any actual danger. Repeat the next day.

Your kids are going to cry sometimes. That's life. You can not protect them from everything, and trying to will cause more long-term emotional damage than just having them learn early on that things can not always be absolutely perfect

My pov: working in a kindergarten in Finland.

It's really up to the parents but very few took advantage of the option to stay with their kids the whole time for weeks on end.

Anyhow, most of the time, however clingy and teary the kid is, they come around a few minutes after the parent left and start having a good time.
Parents need to be told this, encouraged to let go just like the kids.
And then it depends how the parents react when they pick their kid up: do they fuss, do they have a bad conscience, do they even ask the kid if it was sad, in other words, do they enforce and even reward the clinging, or do they encourage them to take their first steps into independence?

I'm not saying it isn't hard for kids, going to kindergarten for the first time. Social pressure, stress. But it's harder if parents are very protective and/or the kid had very little contact with other kids until then.

No idea what the situation is like where you live, but I'd go mad if I had 10 kids + 10 parents during the whole day for a whole week.

edit: hmm, this is also age dependent. I was working with kids 3 and up.

Just a heads up that while temporary separation anxiety is common, it can actually be a disorder (separation anxiety disorder) and if you're concerned your kid is unusual in this respect you should talk to a child psychologist.

There is effective treatment available once diagnosed (fluoxetine is amazing and could make a massive difference)