Shirdi being the Holy and most popular pilgrims among Hindus,thousands of visitors flock to Shirdi daily.You have to plan your trip accordingly to get most out your pilgrimage.
The best time for visiting is considered between the monsoon seasons which is between June and August.Because at this time the Weather is more welcoming with cool breeze and drizzling which makes your Shirdi trip really worth.

The three major festivals of Shirdi are
Between March - April - Ramnavami Celebrations
In July - Gurupurnima - Full MoonDay
On October - Shri Sai Punyathithi (Vijayadasami) Celebrations
You can also plan a trip at these Festivals but beware of overcrowd.
At these Festivals seasons Shirdi gives you a vibrant look with Bhajans and musics,pooja and rath yatra (processions with palanquin).

Also you can visit Shirdi during Gurupurnima which comes in the end of July.

Among these Festivals,Vijayadasami is considered the most important because Saibaba letf his heavenly body and attain Maha Samadhi on this day.The day is also celebrated as Shri Saibaba Mahasamadhi Day.It is also named as Sri Sai Punyathithi.

To make your trip really enjoyable and spiritual you can visit Shirdi at festival times.