The api documentaiton for blackout dates for putting / posting currently implies parameters are all at the top level of the object. Like this
{
start_date: DATE
end_date: DATE
}
However, this doesn't work. It does work if it's wrapped in a blackout_date.
{
blackout_date: {
start_date: DATE
end_date: DATE
}
}
Here's where I'm referring to:
https://canvas.instructure.com/doc/api/blackout_dates.html