This page lists the current Udemy special offers and promotions, together with validity dates.
If you need more information on Udemy, please check out this post.
Udemy have changed the way that they manage promotions. Rather than being based on time and/or location, they are based on the student.
What this means is that the offers you see will probably be different from what someone else sees, as they are specific to you.
I hope you find something that helps and/or interests you.
May 15-26 – Udemy Learn Fest
Between the 15th and 26th of May, all new and existing users see a price of $10.