The Happy Little Timer (HLT) serves as an accurate, accessible, fully enclosed, and intuitive custom timer that even children will find easy to use. The timer could be used as a simple time-keeping tool, but the visually appealing design and simple user controls make it extremely accessible to children who may be learning how to tell, count, and/or set time. The HLT uses four large tactile buttons to set any time they desire between 00:01 and 59:59, start the timer, and reset or cancel the timer. It also features a dial potentiometer that can be used while setting the time to change between three brightness levels. An Arduino Uno is internally used to process user inputs, store the desired time, and count time with < 1 sec/min error. A TM1637 Seven-Segment display is used to show the active time to the user. Additionally, a NeoPixel 24 LED Ring was used to make the timer visually appealing, showing a rainbow when setting time and cycling color once per second while the timer is running. An LM7805 voltage regulator circuit was designed to provide 5V to all devices, and an NMOS transistor and K50 speaker were used to create an audio signal driver. When the timer is elapsed, the Arduino emits a 440 Hz square wave to the audio driver, creating an easy-to-hear alarm tone. For those who may be hard of hearing, the LED displays also flash at 2 Hz to serve as a visual indicator. The timer can then be reset and reused, running indefinitely until the power switch is turned off, or the system is unplugged. The Happy Little Timer was the result of a term of hard work, requiring learning PCB design and Arduino programming. The largest accomplishment is making our User Interface, featuring a perfectly fitting, laser-cut front panel and acrylic shield, to allow user interaction while still being an IP43 rated device. We struggled with the physical implementation of the device, having to redesign the enclosure multiple times. The device wiring is a result of this struggle, and would be the first redesign given the opportunity. If more time was allotted, the HLT would also benefit from being able to count up to or down from the specified time at the flick of a switch, or programming the NeoPixel Ring to serve as a visual indicator of how much time is left.