Liftoff of the first crewed launch from the US in 9 years was scheduled for 2020-05-27T20:33:31Z from Historic Launch Complex 39A at the Kennedy Space Center, but the launch has been scrubbed due to weather. The backup opportunity is at Saturday, May 30, 2020 7:22 PM .
Live coverage from NASA and SpaceX:
Docking is scheduled for 2020-05-28T15:39:00Z and hatch opening is scheduled for 2020-05-28T17:55:00Z
Backup launch opportunities: Saturday, May 30, 2020 7:22 PM and Sunday, May 31, 2020 7:00 PM
50% Probability of Violating Weather Constraints, so it’s not ruled out yet by any means. The plan is to go through the count right up to a few minutes before liftoff. The weather only needs to be right at that exact moment.
It’s similar in terms of weather at the launch site, but with crew they also need to consider weather at potential abort sites up the East Coast and across the North Atlantic.