I am attempting to add a Youtube video to my blog post with a custom time (notice &t=2215s fragment from the URI). Apparently at the moment the validation doesn't allow me to do that which is rather annoying.

Sorry for cross-posting this https://www.wix.com/code/home/forum/community-feature-request/blog-insert-youtube-videos-with-custom-time%3Fpage%3D1%26dl%3D5c4584775fd0a800cb186734 - I had no idea that I can post this here.
Hi Gali,
Thanks for contacting us.
You can use the HTML embed feature instead. Here's how:
Go to the video page on youtube
Click on Share and select Embed
Mark the checkbox "Start at" and copy the code
On the post editor, click on the HTML embed icon and add your code.
Let me know if you need any further help.
Thanks for the alternative solution!