Raspberry Pi Stack Exchange
Raspberry Pi Stack Exchange

Questions tagged [timekeeping]

Use this tag for any question related to keeping accurate time. Note there is a more specific "NTP" tag for questions related to that.

This is a catchall category. If you are aware of NTP and the question is about that, use instead.

70 questions
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Where does the Raspberry Pi get the time from?

I don't have to set the clock (besides the timezone) on the Raspberry Pi. Where is it getting the time from? About how accurate is it?
Scoop
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How is time kept on the Raspberry Pi?

How is time kept on a Raspberry Pi with the latest Raspbian release? What sets the internal clock from an NTP server? What happens when no NTP server is available? From my program I am trying to determine if the time has been set from NTP and ask…
Guy
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4 answers

How accurate is Raspberry Pi's timekeeping?

I realize that since Raspberry Pi doesn't have a hardware real-time clock built in, some issues with accurate timekeeping may present themselves, even when persistence across reboots is not a requirement. This can largely be mitigated by running a…
user13
17
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3 answers

Time and timezone issues on Raspberry Pi

I've a Raspberry Pi that I was using in the EST timezone. It had an NTP service installed (sudo apt-get install ntp) and the Raspberry Pi was set to the UTC timezone. The date on the Raspberry Pi was correct, until I took the Raspberry Pi to the…
Ninja
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11
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8 answers

Raspberry Pi won't update time

I bought a Raspberry Pi 3 approximately two months ago, and since then time has never updated. Details: The operating system is a fresh installation of Raspbian Jessie (4.1.19-v7+). The Internet connection is via native Wi-Fi and no other problem…
Pygmalion
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9
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4 answers

After reboot, my RPi is one hour off -- How to adjust for Daylight Savings problems?

The electricity to my apartment went out a few days ago. I use my RPi to record data and store it in a database. I've just learned that the time for all my data has been off by an hour because the RPi's clock is off by an hour. From here I issued tz…
Matthew Moisen
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3 answers

Switch out the X1 Oscillator on a RPI 2/3

Just like a lot of people I'm using a RPi as a NTP server (more info about the basic setup here: https://framkant.org/2017/03/stratum-1-ntp-server-with-freebsd-on-raspberry-pi/) I have found that the stability is really bad and it's especially…
Peter
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3 answers

How does Pi keep track of time interval?

As I understand RTC is needed to keep track of time. However, Raspberry Pi does not have that and use NTP servers to synchronize its time. All that is fine, but how does Pi know that one millisecond or one second has elapsed. How is Pi aware of the…
AppleGrew
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2 answers

How do I set Raspbian to use the primary time server time.nist.gov?

I have several Rpi3s running Raspbian. They collect data and I use FileZilla to copy data from one to another. Ideally, I am only copying files that have changes or are new. FileZilla can be installed on a PC at FileZilla download…
SDsolar
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5 answers

LibreELEC: Fix date

Using LibreELEC v7.0.2 with Kodi 16.1 on a Raspberry Pi 3. The date and time is incorrect. It can temporarily be fixed by SSH'ing and running date --set with a provided date. But on boot, the date resets to the date when Kodi was compiled: June 22…
Katherine
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6
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2 answers

Make RPi keep an semi-accurate time after power loss

I use Motion detection and a webcam as a security camera. It's headless with no internet or keyboard. To turn the camera off while it's not need I just turn the power supply off. Because I shut it down this way the time doesn't get saved onto the…
11chubby11
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2 answers

Setting up time on Raspberry Pi with Ubuntu LTS 18.04

It seems I am unable to set up permanent time on my Raspberry Pi 3 with Ubuntu LTS. I tried: sudo timedatectl set-ntp 0 sudo timedatectl set-time "2018-09-17 18:17:16" sudo timedatectl set-timezone Europe/Paris sudo timedatectl set-local-rtc…
Wojciech Szabowicz
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3 answers

How can I get a clock in C accurate enough to control a servo?

I want to write a program that controls a servo motor myself using a pi B+. Controlling the motor involves sending 1.5 millisecond pulses along a GPIO pin every 20 milliseconds. I have tested the following stripped-down code on a 32-bit x86 Ubuntu…
axl
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Log correct boot time

I have a Raspberry Pi 2 Model B that I use as a mini server and I'd like to get an accurate reading of the times the system is switched on. The problem is not the shutdown times, which are logged correctly, but the startup ones, since the Pi doesn't…
trillian
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How to display real time on a Pi

How do I give my Pi system a Real Time Clock (RTC)? Is this possible? As each time when I power off my Pi, and the next time when it boots, it displays the previous power off time. Can someone explain me how to initalise or setup a RTC in my Pi?
qwerty
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