Another Elon Musk deadline. Another Elon Musk deadline missed.

The Tesla Inc. CEO on Wednesday said the company would be holding "the official product launch" for the third version of its long-awaited solar roof on Thursday afternoon.

But Thursday afternoon came and went without any announcement from Tesla. Musk tweeted at 6 p.m. Thursday that the announcement was being delayed until a conference call at 5 p.m. on Friday.

Musk's tweet ended a day of mystery surrounding the solar roof announcement. State officials, who spent $750 million in taxpayer money to build and partly equip the Tesla plant in South Buffalo that will make the solar roof, said earlier Thursday they were equally in the dark about Tesla's planned announcement.

It's the latest in a long line of missed targets by Musk, who has a long history of promising bold initiatives on ambitious timetables, only to miss his own deadlines.