How to create custom date display format in drupal 7? I have created content type for an events in which I mentioned multiple values for date field. I want to display date like Nov. 2, 6 &amp; 8   or Nov. 2-5, 12 2014 &amp; Jan 22 2015   

After some research I am able to create a view of event date field like 

Nov 23 2014, Nov 26 2014, Nov 30 2014, Jan 03 2015 to Jan 05 2015

But still not getting format I want like

Nov 23, 26, 30 2014 &amp; Jan 03-05 2015
If you are comfortable with coding then go for template file changes.
You have to do changes in node.tpl.php.

Else you can do also without coding refer https://stackoverflow.com/questions/8375674/how-can-a-custom-drupal-date-format-be-added

If you have created view for event display then it is easy to display date field as you want.
Go to date fields setting. There is a option for formatter. Like below screenshot. Here you can add custom date display format.