1. Please add all the dates on which you have the conference by clicking Add Another Date
2. Input the Start Time and End Time which is common for most of the dates.
3. Click Next
4. In the Slots screen, scroll to the date which has a different Start Date and/or End Time 
5. Delete the slots which are not needed for that Dates (or)
6. Click Add Another Opening and add the extra slots for that date
7. Click Next
8. Select the Recipients
9. Click Done
10. Click Send