-- Sunday started out as a normal day waiting tables for Claire Hudson.
The 25-year-old was working a double shift for her job at local burger joint, Mac's Grub Shak, when something amazing happened.
"It was actually a really slow day and then this couple came in," said Hudson of Spring Hill, Tennessee. "I didn’t even realize the tip until after they were gone."
The unidentified diners had left a $36 tip on a bill that couldn't have been more than $30, Hudson told ABC News.
"I would’ve liked to have caught them and said 'hey this is awesome!,' she said. "They did it anonymously and it was really sweet."
In addition to the $36, the couple also left Hudson with a note explaining the heartfelt meaning behind the digits.
"Today is my brother's b-day," it said, written behind the credit card receipt. "He would have been 36 today. Every year I go eat his favorite meal (hot dogs) and tip the waitress his age. Happy B-day Wes."
"I was in tears when I read it," Hudson said. "I had to go in the back of the restaurant and compose myself before I went out to my other tables."
About three hours after the experience, Hudson posted an image of her customer's note on Reddit.
"When I woke up I was on the front page," she said. "It had over 1.5 million views on Imgur and 350K upvotes on Reddit."
In light of her story going viral, Hudson and the restaurant owner hope to track down the kind patron that left the tip.
"We want to see what his brother Wes liked on his hot dogs because we'd like to name a hot dog after him," she said.
"I have a friend, he was my best friend, he died about three years ago. This experience has definitely given me the idea to do the same thing on his birthday every year. It was deeply moving and just the coolest thing that’s ever happened."