I see no picture here.

You are using here a 3rd party extension where the calendar is displayed in a list.
This is not a Joomla issue. Please ask for help in the forums.

Ok, can you give me the url ?
Thanks

Please ask help on the forums. This repository concerns in first Place Joomla-Core coding. For this Reason closing this Issue, thanks.

Set to "closed" on behalf of @franz-wohlkoenig by The JTracker Application at issues.joomla.org/joomla-cms/20201

It is sad that in this case, there is a willingness to perfect the scope of the calendar : #19944
and not in this case...
what a pity

@franz-wohlkoenig I'd suggest reopening this. I am not so sure this is a 3PD issue. We are basically saying the calendar cant be placed in a table.

Set to "open" on behalf of @franz-wohlkoenig by The JTracker Application at issues.joomla.org/joomla-cms/20201

reopened as stated above.

We are basically saying the calendar cant be placed in a table.

Isn’t also subform build with tables? I think in that case the calendar works pretty decent, so I have no clue what the css used in such case

if you have a CSS rule like:

... div {
    position: relative;
    overflow-y: scroll;
}

e.g. in this case something like

td > div {
    position: relative;
    overflow-y: scroll;
}

and it matches the outer container of the calendar you will get this effect
because the calendar is placed inside

<div class="field-calendar">
   <div style="direction: ltr; position: absolute; box-shadow: rgba(0, 0, 0, 0.67) 0px 0px 70px 0px; min-width: 0px; padding: 0px; display: block; left: auto; top: auto; z-index: 1060; border-radius: 20px;" class="js-calendar">
  ...
  </div>
</div>

there is no CSS rules for .field-calendar,
and if something override the defaults you will get issue like this

Indeed it is not a bug but, some inline CSS for outer container .field-calendar would help ?

Actually there is no guaranteed fix for this
even if you add CSS for .field-calendar that will be hard to override (e.g. inline)

Still someone can place the calendar inside a box with relative positioning, with a limited height and overflow hidden or scroll

Only guaranteed fix would be to have the calendar popup placed under body,

but then you (might) have other problems trying to keep the calendar positioned at the place that it was opened that will even depend on browser, still i think it is worth doing

Actually there is no guaranteed fix for this

Well there is: web components and shadow DOM. But not for J3 :(

Set to "closed" on behalf of @jwaisner by The JTracker Application at issues.joomla.org/joomla-cms/20201

Closing this as it has been confirmed as not a bug in J3.