NIE approved on June 28th with travel window between July 15th to Aug 15th

I have attended my visa interview in Delhi on June 28th and NIE got approved with annotation on my passport with a travel window between July 15th to Aug 13th and received the same in email confirmation. Due to family event I would like to extend my travel for one more week and decided to travel on Aug 21st. A recent update from the government says that NIE’s are valid for 12 months and multiple entries. Will I fall in the new rule or should I travel within the travel window that was given to me?. Should I reapply for new NIE or can I travel with existing email confirmation?

Thanks in advance

You don’t need anything except the copy of below. This updated was published on 29th June, a day after your NIE was approved so maybe you got the 30 days travel window email due to that.