## RTC
> A real-time clock (RTC) is a computer clock (most often in the form of an integrated circuit) that keeps track of the current time.
> ([Wikipedia](https://en.wikipedia.org/wiki/Real-time_clock))
[](https://www.alza.sk/asus-prime-h310m-r-r2-0-d5535927.htm)
## Time Epoch
Unix port uses standard for POSIX systems epoch of `1970-01-01 00:00:00 UTC`. However, embedded ports use epoch of `2000-01-01 00:00:00 UTC`.
## Notable Epoch Dates
| epoch | usages |
| ---------- | ------------------------------------------------ |
| 0.jan.1 BC | MATLAB |
| 0.jan.1900 | MS Excel, IBM Lotus Notes 1, 2, 3 |
| 6.jan.1980 | GPS |
| 1.jan.2000 | microcontrollers, *PostgreSQL*, *ZigBee UTCTime* |
## [`utime`](http://docs.micropython.org/en/latest/library/utime.html)
> The time module provides functions for getting the current time and date, measuring time intervals, and for delays.
## [`gmtime([secs])`](https://docs.micropython.org/en/latest/library/time.html#time.gmtime)
* in module `time`/`utime`
* convert the time `secs` expressed in seconds since the *Epoch* into an 8-tuple
* if `secs` is not provided or `None`, then the current time from the RTC is used
## [`time([secs])`](https://docs.micropython.org/en/latest/library/time.html#time.time)
* in module `time`/`utime`
* returns the number of seconds, as an integer, since the *Epoch*
## NTP
> The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.
> ([Wikipedia](https://en.wikipedia.org/wiki/Network_Time_Protocol))
## [chrony](https://chrony.tuxfamily.org)
## [www.ntppool.org](https://www.ntppool.org)
## UTC
Coordinated Universal Time
notes:
* https://www.space.fm/astronomy/earthmoonsun/primemeridian.html
[](https://www.rmg.co.uk/royal-observatory/attractions/stand-on-prime-meridian-line)
## Named Time Zones
| short | name | UTC |
| ----- | --------------------- | ------ |
| CET | Central European Time | +01:00 |
| PST | Pacific Standard Time | -08:00 |
| MSK | Moscow Standard Time | +03:00 |
## Timezones Support in MicroPython?
[](https://imgs.xkcd.com/comics/iso_8601.png)
`2022-03-20T12:34:56+01:00`
[](https://bigtimeclocks.biz/blogs/news/how-a-radio-controlled-clock-works)
notes:
* https://bigtimeclocks.biz/blogs/news/how-a-radio-controlled-clock-works
