Today is April 30, the last day for lottery winners to pay the $15 per hiker fee and accept their slots. In past years, quite a number of won slots are never accepted, and at the end of Apr 30, those slots are made available to anyone via the Recreation.gov website. The slots become available at random times throughout the day on May 1, not all at once.
So tomorrow, if people want slots, checking in often is a good idea.
Here are links, set to July 1. You may need to enter a group size, and click "Find Permits" to see what is available.DAY USE of Mt. Whitney ZoneMt. Whitney Trail Overnight Permit