|Specifics: This is for IDW Comics|
The calendar's vegetable-themed pinup girl seems to randomly change.
c.1975 While surveying the contents of seventeen crates of old stock photographs he'd bought as a lot at an auction, calendar publisher Werner Gischman came across a treasure-trove of photos; a twenty-year collection of ravishing pin-ups of Parade Queens from New York Thanksgiving Parade. Gischman recognized the goldmine he'd stumbled upon, a nostalgic pin-up craze was sweeping the nation in '75, and he rushed to print the collection as a sixteen-month calendar.
What Gischman didn't know was that the photos, when arranged in a certain order, deciphered a code that points toward the true origin of the Devil (an origin that, as it turns out, is far less impressive than most people think).
Foresworn to protect this secret for untold generations, dark cultist sect, The Vigilant Legion of the Black Pit, realized the calendar had reached store shelves too late to stop it. In a last-ditch effort to keep the code secure, the Vigilant Legion cast a spell over all the crates of calendars, so that the pages would flip and switch constantly. As it turned out, nobody was really interested in Parade Queens from the 50's and 60's, and the calendar sold less than a dozen copies. The Vigilant Legion bought up most of them, and Gischman gave the rest to friends and family at Christmas. Embarrassed by their alacrity, the Vigilant Legion of the Black Pit murdered them all anyway, just to be thorough.
Where to Find ItEdit
In the Field: After leaving the juvenile book section, Ray and the Rookie will enter a small room where the Gray Lady will fly up a set of stairs, collapsing a bookcase behind her. There is a small alcove to the right of the blocked stairway, in which the calendar can be found. Blast the chair lodged underneath the doorknob to get access. It is just before Special Collections.
At the Firehouse: On the second floor in the bathroom/shower room, on a wall above the metal trashcan.
Secondary Canon HistoryEdit
The Pin-Up Calendar of Doom! was hung up in the Paranormal Containment Research Tank. During one summer, the theme for the month displayed was watermelon.
- In Ghostbusters Volume 2 Issue #18, the calendar girl on March is based on Evilyn from the Ghostbusters of British Columbia fan franchise.
- In Ghostbusters Get Real Issue #2, page 17, the woman in the pin-up is based on LunaxMars from The Ghostbusters of New Hampshire fan franchise. She did a picnic photo with Capitol Bombshell - Boudoir & Pinup Photography.  
- In Ghostbusters Annual 2017, on page 39, the calendar is on January.
- The model is Mrs. Stay Puft from Arda Wigs circa 2016. 
- The lineup of the January matches with January 1998.
- On page 6 of Ghostbusters 101 #2, in panel 6, on the Pin-Up Calendar of Doom! is Ziggy Zeigler, an unaffiliated Ghostbusters fan residing in Florida.
- On page 3 of Ghostbusters Crossing Over Issue #5, in panel 5, the month the Pin-Up Calendar of Doom! is on has a picture of a Twinkie.
- Ongoing Series
- ↑ LunaxMars Facebook post 8/7/15
- ↑ Ghostbusters of New Hampshire Facebook post 8/7/15
- ↑ Arda Wigs Tumblr post