Stack Overflow
Stack Overflow

Questions tagged [ntp]

Network Time Protocol is an application level network protocol that is used for synchronizing clocks of computer systems. The term also refers to the reference software implementation.

The Network Time Protocol version 4 is defined in RFC 5905, RFC 5906, RFC 5907, and RFC 5908. NTPv4 is also suitable for the Internet Protocol version 6 address family.

The reference software implementation is provided by the NTP Public Services Project.

http://en.wikipedia.org/wiki/Network_Time_Protocol

693 questions
18
votes
5 answers

How to prevent usage of expired license through system clock tampering?

I am currently working on a license manager using java, I will be specifying a start and end date for my application so I can force a licensed user to re-license the program after a certain amount of time. But the problem I am facing is that any one…
Lalchand
  • 7,627
  • 26
  • 67
  • 79
16
votes
1 answer

Android: Getting the date and time from a NTP server

I would like to obtain the date and time from my own time server (i.e. 192.168.1.X) for the use inside my Android application I have searched in the web and there are two solutions: solution 1 solution 2 However, I was wonder if there is any…
MW_hk
  • 1,181
  • 4
  • 14
  • 39
13
votes
2 answers

How do I establish clock synchronization in the cloud (AWS, heroku, etc) across many nodes?

I would like to run a large cluster of nodes in the cloud (AWS, Heroku, or maybe self-manged VMS), whose clocks must be synchronized with a predefined tolerance in mind. I'm looking for a tolerance of maybe 200 ms. That means if I have 250 nodes,…
Bernie Habermeier
  • 2,580
  • 2
  • 22
  • 20
13
votes
2 answers

Synchronize time in javascript with a good precision (>0.5s) (NTP-like)

I'm looking for a way to synchronize time between clients with a good precision (let's say 0.5 seconds at least). I exclude using jsontime or exploiting timestamp in server response headers due to a poor precision (a second or maybe…
micred
  • 1,482
  • 1
  • 19
  • 19
13
votes
2 answers

Windows API to trigger the time synchronization

Is there a windows API that would achieve the equivalent of clicking the "Update now" button in the "Date and time properties"/"Internet time" tab (opened by double clicking the clock in the taskbar)? Is there a way to monitor when the time…
Hrvoje Prgeša
  • 2,051
  • 5
  • 21
  • 36
12
votes
4 answers

How do you get a timestamp in Arduino-ESP8266?

I would like to get a timestamp with Arduino-ESP8266. But I don't have any idea how to get that. I suppose we have to get the time from the Internet since the ESP8266 doesn't have any clock. Do we need to do that only once or every time we need a…
stallingOne
  • 3,633
  • 3
  • 41
  • 63
10
votes
3 answers

JavaScript NTP time

I'm writing a counting script who counts the time between an old date and today. Everything worked good until I tested on a computer with wrong date and saw the results. So I found a way to get NTP time via…
David
  • 103
  • 1
  • 1
  • 4
10
votes
5 answers

How to get time from an NTP server?

I need to get the time for the UK from an NTP server. Found stuff online however any time I try out the code, I always get a return date time, the same as my computer. I changed the time on my computer to confirm this, and I always get that, so it's…
RobouteGuiliman
  • 191
  • 3
  • 3
  • 11
10
votes
1 answer

ntp questions: slewing versus jumping the time

ntp doesn't want to jump your clock, because discontinuous time jumps are Bad. It wants to adjust your clock gradually -- very gradually. It's very conservative: by default, it won't slew your clock by more than xx parts per million (ppm). But…
Steve Summit
  • 45,437
  • 7
  • 70
  • 103
9
votes
3 answers

How to get NTP working with custom I/O Pin?

I have a motherboard with I/O pins and I have written a C library with functions to set and query the status of these I/O pins. Lets say the name of one of these functions is get_pin(int pin_no), and it returns the logical voltage of that pin. I…
DeepDeadpool
  • 1,441
  • 12
  • 36
9
votes
6 answers

Failed to restart ntpd.service

I'm trying to fix error RequestTimeTooSkewed i get when trying to deploy a project to amazon servers i found this article. http://www.emind.co/how-to/how-to-fix-amazon-s3-requesttimetooskewed/ I was following the steps but stucked at restarting the…
Alpha Dog
  • 193
  • 1
  • 2
  • 6
9
votes
3 answers

How to detect change of system time in Linux?

Is there a way to get notified when there is update to the system time from a time-server or due to DST change? I am after an API/system call or equivalent. It is part of my effort to optimise generating a value for something similar to SQL NOW() to…
ϹοδεMεδιϲ
  • 2,790
  • 3
  • 33
  • 54
9
votes
2 answers

Retrieve Time from NTP server via PHP

I have an issue with a Virtual Machine (VMWare/Ubuntu) that is getting out of time sync. We decided that the best thing to do was to get the time directly from an NTP server so I started researching a script to do that but nothing works so far,…
Carlos M.
  • 168
  • 2
  • 2
  • 12
9
votes
2 answers

How can I get the actual date and time if the device date and time are inaccurate?

I noticed that if I set my device time manually, and turn off the automatic time sync on my iOS device, [NSDate date] returns the date and time assuming the device time is correct--which it may not be. Since the docs mention that NSDate has some…
Anton
  • 3,998
  • 25
  • 40
8
votes
3 answers

What are all the fields in a Python ntplib response, and how are they used?

I'd like to make a measurement of the difference between a local clock, and a remote processor running an NTP server. I can get the tx_time of the response, as shown below, but a better estimate would include some estimate of the network delays. …
Matt
  • 500
  • 1
  • 12
  • 21
1
2
3
…
46 47