The opening scene clearly shows the same calendar being used for both 1988 and 1998. And moreso, it says that Halloween fell on a Thursday in both years. However, Halloween in 1988 was actually on a Monday, and in 1998 was actually on a Saturday.
At approx. 6:30, when Tiffany is about to enter the closet, the shadow of the boom is visible on the door for a second.
Near the end of the episode, Tiffany panics when her flashlight dies. Seemingly forgetting that she just put on a belt with several other flashlights on it before she went into the closet.