Haven't spread my trade yet.
MU earnings release is on a Thursday, so there are games that could be played. I haven't sold Calls yet as I feel it's guaranteed that MU beats and goes higher.
My trade is still just a purchase of Calls, and I wanted an extra week for MU to respond after earnings release (as I expect a gap higher on the day-after, June 30) so my purchased Calls expire July 7.
I think it pays to wait and sell the overhead Calls on the day after earnings release (which would be on a Friday). Now there's two choices for expiration date of the sold Calls. In the ideal case the Calls being sold expire worthless. A game that could be played is to sell Calls that expire on the Friday immediately after earning release; then if not assigned, sell Calls again for the following week.