I ran into this recently. The case was a forum with a bunch of pinned topics from 2021 that had also been closed. It’s clear that they want to keep the topics pinned, but seeing the old dates at the top of a topic list makes it look like the forum doesn’t get much activity.
Yes. As an admin user, go to the pinned topic and click the admin wrench icon that’s on the upper right of the page. Select “Change timestamp” from the dropdown menu. That will allow you to update the topic’s date.
Another way to deal with it would be to hide the dates of the pinned topics with CSS. Something like the following, added to your theme or a theme component should work:
.topic-list-item.pinned .activity.last {
display: none;
}
or to just target mobile devices:
.mobile-view .topic-list-item.pinned .activity.last {
display: none;
}