I can think of two issues.
The first is that you are trying to apply the date picker to an ID of “datepicker”. You have 2 such IDs in use. So, only the first will get the date picker.
The second is that that tab content does not exist until after the modal is instantiated. This takes a few cycles. By that time, Angular has already done a digest and looked for all directives in the HTML. It found none for the modal because it did not exist yet.
See this fork : http://plnkr.co/edit/0RdP9bB93J0l6ibK7O3l?p=preview
I used 2 different picker directives and didn’t try to create the second picker until you open the modal.
It needs refinement, but that depends on your final application. I’m assuming you aren’t going to actually have 2 data pickers.