My husband (63 years old) and I (61 years old) day hiked to the summit on July 23. We didn't have permit reservations, but showed up at the Visitor Center the day before at 11:00 and got two permits. (There were 10 cancellations, but we were the only ones there who wanted permits.) Thanks to Versatile Fred for all the info on getting permits at the last minute!
We stayed at the Comfort Inn in Lone Pine (the Dow Villa was full), which was fine. We got up at 3 am on the 23rd and left the trailhead at 4 am, got to the summit at 12:00 noon, got back to the trailhead at 7:30 pm. Neither of us suffered any altitude problems or felt sore the next day. We had acclimated at Mammoth for 2 days (hiked to Duck Lake and Lake Ediza, as warm-ups for Whitney). We live in the San Francisco Bay Area.
For breakfast on the 23rd, we each had a banana, a granola bar and a PB&J sandwich. While hiking, we ate gels (Gu and Cliff Shots), sport beans and Cliff bloks, Luna bars, Ritz cracker-and-peanut butter sandwichs, and PB&J sandwiches. We got water at Trailside Meadow and on the switchbacks both going and coming. We each carried 100 oz Camelbaks, but only filled them full at the switchbacks on the way up. Otherwise, they were about half full.
The day was perfect. Sun, no clouds. No wind. Colorful sunrise. Great visibility from the summit. Wildflowers everywhere along the trail. The Sky Pilots on the switchbacks were especially beautiful. We only needed our headlamps for about an hour on the way up and not at all on the way down.
Our hike was a big contrast to last July, when clouds and altitude problems made us turn around about a mile below the summit. This year, no problems at all!
Thank you so much to everyone who's posted on this message board with info about the hike. We took advantage of all the advice and our day was wonderful.