Creating a clock using Arduino I want to make a large clock, 16 inch x 7.5 inch, which will display dd Month yyyy.
What would be the best way to do this?
Does Arduino have a built in clock, and I'd just need logic to turn on/off LEDs on a display that already has dd Month yyyy? Do such displays exist which I can connect to Arduino?
If you are willing to go the “barebones” route, you can turn an
ATmega328P (the MCU at the heart of the Arduino Uno) into a very
accurate RTC by hooking a watch crystal to it's clock pins. Given proper
calibration, you can get an accuracy of a few seconds per year.

This would require some coding though, and is not as straightforward as
using an off-the-shelf RTC. C.f.
this answer for the details.