When items are entered with dates, they appear in the Calendar like this:
L9 The real Oscar awards 1st UU Church
L8 SYC Auction 1st UU Church
D30 New Orleans Dinner Su Ann Farnlacher
D12 Heart Healthy Brunch Rebecca Wolff
L10 Circle Supper 1st UU Church
X15 Jungle Jim's International Market Road Trip Sandy Coen & Florence Jain
You can make items appear only on the calendar and not the catalog by making their qty=0 but with an event date.
Sometimes people use a different category for these non-item items to keep them separate and avoid gaps in the item numbers. If you do that, remember to disable that category except when you want to add or edit the calendar-only items.
Sometimes, an item from one year's auction gets posponed or rescheduled into the next auction's time period. In that case, you may see the calendar year in parenthesis, indicating the event is a carry forward from last year.