Hi Tabinda,
When you select an already selected date in the Multiselect Calendar that date will be deselected and will be removed from the list, so the last date selected will be set in args.values.
For Example: If 5, 10, 18 and 25 are selected and if you select 18 again then 18 will be deselected and will be removed from the list of selected dates and then the last date which is selected (here 25) will be set in args.value.
Hence it will return 25 not 18.
I have attached the video to demonstrate the scenario explained above. Hope this will help you.
Also can you explain your requirement so that we may also assist you with a solution to your requirement.
Regards,
Joseph Christ Nithin I