rtime

Prints the current time as days since January 1, 1970, UTC; milliseconds since midnight, UTC; time zone offset from UTC in milliseconds; and daylight saving time offset from UTC in milliseconds. These four values define the current time as kept by the software real-time clock in RainbowDashboard.

Option	Description
‑d	Prints the four values as decimal integers; the default.
‑h	Prints the four values as 8-digit hexadecimal integers.
‑b	Outputs the four values as 32-bit big-endian binary data.
‑r	Outputs the four values as a series of RainbowDashboard commands that set the clock on the Rainbowduino.
‑f	Outputs the current values of all 64 individual clock fields. See Fields.

You can set the clock on the Rainbowduino by simply redirecting the output of rtime -r to the Rainbowduino's serial port using aecho or rainbowd. The 'r' in rtime stands for 'Rainbowduino.'