That's not what the date means, if google finds a date in the meta then it uses that to influence it's results. It's good for news websites because latest articles are crawled with a more recent date and appear first, but when it's a static homepage it badly affects ranking.
There are wordpress plugins that achieve this, is it not possible for something similar?
https://www.bloggingtriggers.com/hide-remove-date-google-search-results/To put it into simpler terms - Google thinks my homepage is a blog post and found a date somewhere in the meta snippets and now it will fall down search rankings as it's forever thought to be an old blog/news post. It's a common issue with Wordpress websites and of course, solutions like OSClass that are built on the framework of wordpress and solutions are available for Wordpress sites but it doesn't seem like anything has been done for OSClass in that regard.