How to check support time for package without installing it?

https://packages.ubuntu.com/focal/lxterminal
Support for the Focal packages are for the life of the version of Ubuntu.

OK, but we talk about Bionic. I checked with ubuntu-support-status and I can see that libavcodec57 have support until April 2021. So this is why I asked you about it. I want to check support date by website like packages.ubuntu.com but I can't see this option.

The only information that you need to know is whether the package is from 'main' or from 'universe'.

On https://launchpad.net/ubuntu you see for each source package the repository bucket in which it is categorized.
This information is also copied to packages.ubuntu.com

E.g. for https://packages.ubuntu.com/focal/lxterminal it tells 'universe' and consequently The support that it gets from canonical is limited, and it depends on the community.

@Manfred Hampl, okay but it is always the same date for packages from universe? I mean that always it is only 3 years support for all Universe packages or if there are exceptions to the rule ?

My english is not the best but I understand that always packages from Universe have 3 years of support ? Unified support lengths means that always all packages have the same date.

If you keep asking the same question repeatedly, you are going to get the same answer repeatedly. If you want to run Lubuntu 18.04 for two more years, you can, but you will probably not get updates to things like lxterminal unless other Ubuntu users go through the process to update those packages through SRU. Canonical/Lubuntu developers are not obligated to update them.

I don't know how we can make that any clearer. You know the situation. The choice is yours.

Mr Daniel Letzeisen, I don't know what you are mention Lubuntu. In this topic I will not asking you about Lubuntu. You have right, I have Lubuntu but only in one machine. I have a lot of computers. This topic is about libavcodec57 or 58. I know that I mentioned also lxterminal but for example. I have Ubuntu 18.04.5 on one machine (not Lubuntu) and I am little worry that this have support to 2023 year but for example I can't play videos because libavcodec57 is outdated and not supported after this month.

You still can play videos and use livabcodec57. It will not disappear. It is just the case that nobody can guarantee that bugs (in case that they are detected) will be quickly corrected.

Yes, I know that I can use libavcodec57 but if will be some security vulnerabilities (CVE) probably I will not get fix update for my libavcodec57 in the future because this is not maintained after this month so this mean that updated will be not available. Have I right? If answer is yes I will be must removed libavcodec57 in next month and I can't play videos.

In my opinion, this is a total troll job taking advantage of good faith...

https://packages.ubuntu.com/search?keywords=libavcodec&searchon=names&suite=focal&section=all

Why Mr Bernard sen link to focal? We still talking about bionic.

In your original question you wrote

"... package for Ubuntu 20.04 LTS ..."

20.04 is focal and not bionic.
I am sorry, but you are contradicting yourself.

Manferd Hampl you have right. This was my mistake. In first I wanted to ask about support for LXDE environment in focal because I wanted to install it but now I founded that libavcodec57 is not support. I checked this on Lubuntu 18.04.5 and I can see that is not supported at all now. Like I said I have installed Ubuntu 18.04.5 on other machine and I wanted install there libavcodec57 package but I can't because it is not supported. Like I said I can't install focal there because bionic is slow and focal don't work because this have too high minimal requirements.

Thanks Manfred Hampl, that solved my question.