@SBatchI think trading days makes a lot more sense - I guess it doesn't matter if a company always reports earnings on the same day of the week, but as your example indicates it can make a difference for companies whose reporting day of the week varies from cycle to cycle. If this can't be a user-specified settings choice, perhaps a good compromise would be to use trading days for any custom earnings scenario within 2 weeks (up from the 5 days the Ophir cited) and use calendar days for anything outside of 2 weeks?