Many of us, at some point, have come down with a bad case of the "Sunday Night Blues," overwhelmed with that feeling of the workweek looming. Monday is the start of a whole new countdown until Friday 6 p.m., when we can rejoice for 62 hours thereafter until we go back to the same old song and dance for the following week. However, happiness shouldn’t be reserved for only the weekends; we can instantly feel happier throughout the workweek — all drinks aside — without spending money. Just try these eight scientifically proven ways:

1. Put A Smile On Your Face

Yes, it’s that simple. The mere act of smiling can turn you from feeling OK to being happy. Smiling is contagious, so when you smile, others will also likely return the smile, creating happiness all around. To feel better, smiling is best done when it’s associated with positive thoughts. A study led by Michigan State University found customer service workers who smile as a result of harboring positive thoughts, such as waiting to see their significant other or to see their child in a school play, improved their mood and withdrew less from work. Those who fake smiled throughout the way were more likely to worsen their mood and withdraw from work. Remember there’s a noticeable difference in a fake smile and a genuine smile.

2. Lend A Helping Hand

Volunteers are needed year round, rain or shine. A random act of kindness will not only help others be happy, but also make you happier in return. Try to set time aside each week, for example two hours per week, and dedicate it to helping others. The power helping people has on the psyche is highlighted in a study on the collapse of East Germany and its infrastructure of volunteering. Due to the reunification of Germany, a large portion of the volunteering infrastructure collapsed as people randomly lost their opportunities for volunteering. These volunteers were then compared to the control group who had no change in their volunteer status. The findings revealed volunteering is rewarding and is linked to higher life satisfaction.

3. Get By With A Little Help From Your Friends

Whether you have a big social circle or a small intimate tight-knit group of friends, they can do wonders for your happiness and health. Those who are social and have strong relationships are found to be the happiest people as they share the best events of their day with loved ones and encourage them to do the same. Those who have relatively low social interaction are more likely to engage in unhealthy behaviors that impact their health. A study in the journal PLoS Medicine found low social interaction can have the same impact as smoking 15 cigarettes daily, or being on alcohol. Go on, and make weeknight plans with your friends.

4. Turn Up The Music

You may be tempted to play some blues when you got the blues, but science suggests to do just the opposite. Listening to upbeat music with your headphones will get you off being down in the dumps and have you start dancing like Kevin Bacon in Footloose. A study in The Journal of Positive Psychology notes the trick to feeling better is to actively listen to the music with the intent that it will make you feel better. When you got the blues, it’s time to put B.B. King aside and play some Katy Perry.

5. Stretch Your Hands & Legs

Busy schedules are often one of the top three reasons people do not exercise. You do not have to be a gym rat, but simply getting a 40-minute workout can make you feel happier and better about your body. When we exercise, we release proteins and endorphins, which are chemicals in our bodies that makes us feel oh-so-good. A study in the Journal of Health Psychology found those who exercised after both 6 x 40 minutes exercising and 6 x 40 minutes reading felt better about their bodies even when they saw no physical changes. Feeling happier and loving your body? Yeah, that seems like a win-win situation.

6. Go Outside, Especially In 57-Degree Weather

Being in the great outdoors on a warm, sunny day can boost your mood in all natural environments. On warm weekdays eat your lunch outside of work, or go on an afternoon stroll after work to soak up the sun’s vitamin D. A study published by the American Meteorological Society found that current temperature has a bigger impact on our happiness than wind speed and humidity, or even the average temperature throughout the day. Happiness can be found at 57 degrees, so be sure to check the weather to get some happiness with a side of fresh air.

7. Plan A Vacation, Even If You’re Really Not Going

While this seems counterintuitive, simply planning a vacation or a private getaway from work can boost our happiness levels. A study in the journal Applied Research in Quality of Life found happiness was at an all-time high during the planning stage of a vacation as people loved the thrill of the anticipation. The effect was so powerful it boosted happiness for eight weeks, but after the vacation, happiness levels returned to normal. Get on your preferred travel site and let your imagination run wild for happiness' sake.

8. Get A Good Night’s Rest

Getting enough sleep is essential to face the upcoming day by giving us more energy and happiness.  Not only will our body recover and repair, but we will be more focused and more productive. Sleep deprivation impacts the hippocampus — where positive and neutral memories get processed — compared to the amygdala, where negative stimuli gets processed. Therefore, being sleep-deprived impairs the ability to recall happy memories while sad memories are found easier to remember. A study in the journal Sleep found sleep affects our sensitivity to negative emotions, such as fear and anger, when we’ve gotten a relatively little amount of sleep.

These eight scientifically proven ways to be happier without spending a dime will keep you happy throughout the workweek and well into the weekend — even on Sunday nights.