Hi @Bilal_Ikram, welcome to the Asana Community Forum 
Thank you for providing this feedback. This was an intentional decision made by our Product team as having a task recur on the 29th or 30th of each month wouls cause issues for tasks recurring in February, which only has 28th days.
I have, however, passed your feedback on to our team. I’ll let you know if they make any changes to this in the future 