Big wall clock

Functions: * time (12/24hr) and calendar (year range 2023 ~ 2099) display
* radio controlled for option (excl.)
* time accuracy: +1s/day
* alarm and snooze function, interval: 5 minutes
* temperature (range: -10℃ ~ +50℃) and humidity (range: 10% ~ 95%, accuracy ±4% from 30% to 85%, otherwise ±7%) display, test period: every 20 seconds