Are you triskaidekaphobic? Triskaidekaphobia is simply fear of the number 13 -- and Friday the 13th has long been considered an unlucky day.
If bandying the words triskaidekaphobia or triskaidekaphobic around the workplace all day will be insufficient to completely alienate your fellow laborers in the vineyard, try tossing "friggatriskaidekaphobia" around instead. (I do hope you're giving a dramatic reading of this post to a group gathered around your cubicle).
Figgatriskaidekaphobia is a very windy term (which I stole from Wikipedia) relating to the specific fear of Friday the 13th.
Sounds like a barely concealed bit of cussing, too, doesn't it? But "frigga" in this usage is not a barely concealed mispronunciation of an all-too-familiar four letter word; rather, it refers to the Norse goddess, Frigg (sometimes rendered Frigga), whose name may or may not have inspired the name of the this day of the week (as Thor inspired Thursday, and Odin -- or Woden -- inspired Wednesday).
Of course, if you're going to get immersed in that discussion, you'd best be prepared to take a position on the ways in which to distinguish Frigg and Freyja, if at all.
Perhaps it would be better to deny any superstitious fears and celebrate instead National French Fries Day. Here is a classic example of a prototypical micro-mini-holidayette: "Honoring" a particular food? Check. Importance inflated by sticking the adjective "National" on the name? Check.
Of course, if you know any French persons, you can probably put their teeth right on edge by suggesting that National French Fry Day is a perfectly appropriate way to get right in the mood for Bastille Day....