(CNN)"What day is it, again?"
It's become a common refrain during the coronavirus pandemic, a reflection of both how all of the days seem to blur together and how lately, we find ourselves forgetting even the simplest of details.
Our internal clocks are shot. Tuesdays are Thursdays are Wednesdays are Sundays. There are no weekdays, or weekends. There is only yesterday, today and tomorrow.
Along with these feelings of disorientation, it may seem like it's getting harder to concentrate and taking longer to complete tasks, as if our brains are just working more slowly.
If it feels like your brain is turning into mush, you're not alone. Experts say it all has to do with how the pandemic is affecting our cognitive health -- meaning, our ability to clearly think, learn and remember.
"It is a perfect storm between changes in environment, loss of social anchors and increases in cognitive stress," said Elissa Epel, a professor of psychiatry at the University of California, San Francisco. "And then on top of that, most of us are not getting the quality sleep that we used to."
Here's what's going on, and what we can do about it.
Our usual routines are gone
Much like our bodies depend on environmental cues like sunlight to regulate our circadian rhythms, they also rely on physical and social cues, explains Epel.
Those cues include routines like morning and evening commutes, set mealtimes or weekly religious services that help us keep track of what day it is.
For those confined to our homes, those routines have largely disappeared. Days have lost their usual structure, meaning once-clear boundaries are now blurred.
"We've lost all of the routine of a typical week, and that means having weekends as a boundary or as a separation or something to look forward to," Epel said. "Now the weekend is the same as a weekday."
Because work is home and home is work for many people, some may find themselves working longer hours or into the weekends. Gone are the happy hours, concerts or sporting events that once separated weekdays from weekends, causing the days to just drag on.
The loss of routine also means more mental energy is spent on determining what each day will consist of.
"When we had our routines, you don't really think about that stuff," said Lynn Bufka, associate executive director for practice research and policy at the American Psychological Association. "So while your commute may be tiring, there's not a second dialogue in your head, trying to figure out what has to happen this day."
For those who still need to go into work, routines may look a lot different. And there's the added mental strain of remembering to socially distance, wear masks and avoid touching surfaces. All of that can contribute to a sense of disorientation.
We're multitasking a lot more
Another reason we can't keep track of the days?
We're multitasking a lot more. Many people are finding themselves balancing multiple responsibilities, such as homeschooling children or caring for an elderly family member -- all while holding down a full-time job or coping with the stress of a layoff.
Because all of those things are now happening in the same place, and often at the same time, we may find ourselves switching in between tasks more frequently. Or we're overstimulated from using multiple screens or consuming news too many times a day. All of these things, Epel said, increase our cognitive load -- in other words, they use up more of our mental resources.
"Our working memory is a limited resource," Epel said. "We can easily tax it by trying to engage in too many activities at once or trying to multitask in our mind."
That's why you might find yourself struggling to recall basic information or perform the tasks you used to with the same efficiency.
"When (people are) attempting to multitask, it makes it more difficult to encode the information that's in front of them," said Inger Burnett-Zeigler, associate professor of psychiatry and behavioral sciences at Northwestern University. "Then the information is not stored and they can't remember what they were doing or what they were saying a moment or a few moments later on."
Those disruptions are causing stress
Not being able to remember what day it is can also be a symptom of stress, explains Burnett-Zeigler.
The pandemic is becoming a source of chronic stress given that it's been going on for weeks, or even months for some people, she said. High stress levels impair our concentration and attention, and can affect short-term memory.
Another effect of stress? It can worsen our quality of sleep.
"Often if you're feeling stressed or you're feeling anxious, those thoughts and feelings can show up and either make it more difficult to fall asleep or more difficult to stay asleep," Burnett-Zeigler said.
That sleeplessness, in turn, can further cognitive impairment, attention and concentration issues and short-term memory loss, she said.
Then again, time is relative
So what can we do about all this?
The psychiatrists and psychologists we spoke to recommended trying to maintain a sense of structure, to the extent possible. Going to bed and waking up at the same time each day is one strategy.
They also recommended taking frequent breaks, exercising, eating healthy and limiting news consumption.
And if it makes you feel better, no one knows what day it is anymore. Time is an illusion.