People often joke about coming down with "a case of the Mondays," but for science writer Bahar Gholipour, Tuesday is the real worst day of the week.
As Gholipour noted in a story for New York Magazine , "Why Does Time Seem to Slow Down on Tuesdays?" , Tuesday is the day when "last weekend feels like it was ages ago," while next weekend still feels "ages away." As a result, time can feel like it's passing more slowly on Tuesdays compared to other days of the week.
It might sound like science fiction, but studies --  including this one on how emotions can subconsciously affect our perceptions of time -- demonstrate that the phenomenon has a foothold in reality. In certain situations, time does seem to move at different speeds.
Why Tuesday Feels Like the Longest Day of The Week
To quote Gholipour:

The brain, studies on time perception have shown, has a strange way of stretching and squishing time depending on the drugs you may be on, the emotions you are experiencing, and even the amount of attention you pay to the moment."

One of the most well-known examples of when this stretching or squishing of time occurs is during life-or-death situations, like car accidents. People often remember such events as lasting longer than they actually did, and even describe time as having moved in slow-motion.
However, research shows that in such cases, the perceived change in time's speed is a function of memory, not perception (i.e., you remember time having moved more slowly, but you didn't actually perceive it that way). What's more, this life-or-death situation research doesn't apply to Tuesdays.
For most of us, we don't encounter life-or-death situations on Tuesdays. In the words of Gholipour, Tuesdays are "dull and unemotional." So, why is it that Tuesdays seem to throw us into some sort of strange time warp?
Gholipour uncovered two promising hypotheses ...
1) The Time Gap
Research shows that the brain "time stamps" events using contextual clues. And things that happen in the same context (e.g., while you're at a party) get grouped together in your memory -- separate from things that happen in other contexts (e.g., while you're in a cab going home). The end result is that we tend to remember like-moments as having occurred more closely together in time.
When applied to Tuesdays, the hypothesis works like this: Going into the office on Monday is such a jolt, such a change from your weekend routine, that by Tuesday the previous weekend feels further away than it actually is.
You see, on Monday, you can still easily tap into your weekend memories because you're still in the process of making that contextual shift from "weekend mode" to "weekday mode." By Tuesday, however, the shift is complete, and you now have your Monday memories -- the beginning of your weekday memories -- blocking the way back to your weekend memories. And this could explain, as Gholipour wrote, why we feel "a vague sensation of a time gap" on Tuesday mornings.
2) Memory Overload
A second hypothesis explaining why time seems to move more slowly on Tuesdays: Our brains simply have more stuff to process during the workweek than on the weekend, and all that processing uses up a disproportionate amount of space in our memories.
During the weekend, we tend to engage in relaxing, predictable behavior (e.g., watching TV, going out to dinner, and so on). During the work week, on the other hand, our schedules tend to become more complex and less predictable. We have emails to read. Emails to write. Assignments to complete. Meetings to attend. On Mondays, we're just getting caught up. On Tuesdays, we're in the thick of it.
Hence, it's possible that our brains generate more discreet memories on Tuesdays, making Tuesdays seem as though they're longer than other days.
As cognitive neuroscientist Virginie van Wassenhove of France's INSERM-CEA Cognitive Neuroimaging Unit explained :

Considering the amount of stuff that you’ve been engaged with during workdays, your recollections of these days are encoded with high granularity, taking a lot of space, so to speak, in memory."

So there you have it: Two possible explanations for why Tuesday feels like the longest day of the week. What's a marketer to do with this information? Well, knowledge is power. And while we can't offer you an insta-cure for the Tuesday blues, the hope is that this insight will help you focus less on the passing of time, and more on the work that needs to get done. 
Happy Tuesday!
Have any suggestions for how we can make Tuesdays feel shorter? Sound off in the comments section below!