Time is a dimension in which events can be ordered from the past through the present into the future, and also the measure of durations of events and the intervals between them.

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111
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How do I get current Unix time in milliseconds using bash?

How do I get the current Unix time in milliseconds (i.e number of milliseconds since Unix epoch January 1 1970)?
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4answers
23k views

Windows Server unable to synchronize NTP time reliably

Why does Windows Server (2008, in this case, but I've seen the same problem in 2003) seem to have problem synchronizing time? I've seen this error in my System log across a variety of servers: The ...
25
votes
4answers
22k views

How to convert 'dmesg' time format to 'real' time format

I have (for example) this log entry in dmesg output: [600711.395348] do_trap: 6 callbacks suppressed Is there a possibility to convert this 'dmesg' time to 'real' time to know, when this event ...
23
votes
4answers
141k views

How do I force sync the time on Windows Server 2008 R2 Domain Controller?

What is the command to sync a Windows server domain controller to its configured time source?
23
votes
3answers
982 views

Risk of starting NTP on database server?

I've heard rumors of bad things happening to database and mail servers if you change the system time while they are running. However, I'm having a hard time finding any concrete information on actual ...
22
votes
8answers
23k views

Should servers have their timezone set to GMT/UTC? [closed]

This may not be a big deal for smaller shops that only have one or a few site, but for larger organizations this is something I'm curious about. What are the pros and cons have having all/most of ...
19
votes
10answers
20k views

Compare NTPD and ntpdate

What are the pros and cons between these two ways to synchronize your server? It seems to me that your server would probably not drift more than 1 second every day, so ntpdate on a crontab would be ...
18
votes
2answers
3k views

What is the largest hardware clock update the Linux kernel “11-minute mode” can make?

When certain time-related programs (like ntpd) are running on a Linux system, the kernel will switch into so-called "eleven minute mode" (see the hwclock man page) whereby it will automatically update ...
16
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3answers
23k views

How can I compare an ntp server's time to my server's time?

I have ntpd running on a box. I want to see how the time on the box compares to the time retrieved from ntp.ubuntu.com. Is there an easy way to do this?
13
votes
8answers
38k views

Need leading zero for batch script using %time% variable

I came across a bug in my DOS script that uses date and time data for file naming. The problem was I ended up with a gap because the time variable didn't automatically provide leading zero for hour &...
13
votes
3answers
4k views

What is a ToD server, “Time of Day” (Not NTP)

I got a simple task: Setup a ToD server... It is not NTP. It runs on port 37. It seems to be bundled with inetd or xinetd. Shall be installed on Debian or CentOS. Alternatively FreeBSD (pfsense ...
13
votes
2answers
2k views

Weird syslog order

Have you ever seen wrong order in /var/log/syslog ? I think that it causes only crontab. Jun 28 22:20:01 alex CRON[2327]: (root) CMD (something > /dev/null) Jun 28 22:21:01 alex CRON[2700]: (root) ...
12
votes
3answers
13k views

Kill process with high CPU usage after X time? [closed]

running linux i have a few processes which tend to crash occasionally (game servers), which end up using 100% cpu. I'm looking for a program or script to check the cpu usage of a list of processes by ...
12
votes
7answers
83k views

Why is ntpd not updating the time on my server?

I have ntpd running on my server. It's all the default settings, except I commented out its ability to be a server to other machines: # restrict -4 default kod notrap nomodify nopeer noquery ...
11
votes
6answers
774 views

Local timezones on servers considered harmful? [closed]

I'm curious as to what other administrators' experiences with timezones, in the context of remotely administered servers, are. In my career I've come across several conventions; Always, always, ...
11
votes
2answers
789 views

Linux kernel detecting wrong processor frequency

After a cold boot of a 6.0.8 Debian server (HP ProLiant), ntpd played havoc with system time: offset and jitter with respect to the usual and reliable reference time servers growing without limit. (...
10
votes
2answers
5k views

What is the clock frequency inside 10Gb and 100Gb Ethernet cards?

As I understand, a 10Gb Ethernet card is capable of putting 10Gb every second on (say) a fibre optics cable. Now naively, for this to happen in hardware, one will need a 10GHz clock running the ...
10
votes
6answers
1k views

Replacing sick NTP server source and re-synching (with internal time currently 2 minutes late)

One of the external NTP servers (the primary one--currently) we're using as source seems to not be responding to NTP calls. Unfortunately, on our core router (Cisco 6509), the NTP functionality hasn'...
10
votes
4answers
3k views

Faking the date for a specific shell session

I'm certainly trying to achieve something weird here, but I want to fake the date locally for a shell session on GNU/Linux. I need to black-box test how a program behaves at different dates, and ...
10
votes
11answers
946 views

What sort of time management system do you use?

System and network administrators are usually very busy people. Juggling projects, meetings, support tickets, and verbal requests from people in the hallways can make a real mess. We've discussed ...
9
votes
9answers
7k views

Time drift

How do you deal with server time drift?
9
votes
2answers
2k views

What is the strategy for detecting time drift in a linux based data centre?

What is the strategy for detecting time drift in all linux based data centre? This is a more difficult problem than it seems at first. Time drift can cause serious problems for certain applications ...
9
votes
7answers
17k views

Setting time zone on linux (ubuntu)

Here in the UK we are UTC+1. I set the time using 'date'. However it keeps resetting back to standard UTC, I'm guessing via a NTP time server. I've tried setting the timezone with tzselect but it ...
9
votes
3answers
9k views

How to make Jenkins CI use Local time instead of UTC on debian squeeze

I have a Jenkins-ci installation on a debian squeeze. Current default time zone: 'America/Toronto' Local time is now: Mon Jul 9 16:00:57 EDT 2012. Universal Time is now: Mon Jul 9 20:00:57 ...
8
votes
6answers
1k views

What consequences / implications can arise from a wrong system clock?

What issues can you think of that may arise from a wrong system clock setting ? Primarily interested in potential problems affecting servers and Linux or UNIX-like systems in particular. And how ...
8
votes
7answers
7k views

Local or public NTP servers?

For a relatively large network (thousands of hosts) - what are the arguments for and against running a locally managed (pool of) NTP server(s) (perhaps periodically set via some public NTP server) and ...
8
votes
3answers
303 views

Managing multi-timezone servers

What would be an ideal time and timezone setup for multi-country servers? Especially considering one central IT team managing these servers. Currently we have each server using a local timezone. e.g. ...
8
votes
3answers
1k views

Easy way to get the International Atomic Time on linux?

My system uses UTC for the system clock, which I don't particularly feel like changing. Is there an easy way to get the current TAI time? (preferably a command line tool or flag)
7
votes
7answers
3k views

Why is the time messed up on my Ubuntu Server VPS?

A month back loads of services on my VPS stopped working. After messing about for an hour or so i worked out that the time had frozen. I gather it was some sort of virtualization bug and a reboot soon ...
7
votes
4answers
829 views

Uptime of a Windows machine

How can one find out 'real' uptime of a laptop? By 'real' I mean the time since turning it on and resuming Windows from hybernation state.
7
votes
1answer
3k views

Single NTP server on isolate network

I have two linux machines (A and B) on an isolated network. They must be time-synchronized. Machine A is powered intermittently and must serve the time, as it is connected to an authoritative time ...
7
votes
3answers
698 views

Record load time of web pages

I have been asked to investigate a way of record how long it a full page request is on our website. i.e. how long it takes from when a user clicks on a link till the page has finished loading. Now I'...
6
votes
4answers
1k views

Ubuntu linux takes longer time for incorrect passwords

When I log into my Ubuntu 8.10 box with a correct password the system figures out almost instantaneously that the password is correct and logs me in. However, if I supply an incorrect password, it ...
6
votes
3answers
15k views

Public NTP servers

Is there a list of public NTP servers on the internet I can use.
6
votes
6answers
14k views

Domain Controller time is incorrect

I have a domain controller running in VM on Hyper-V, the time seems to be steadily getting faster, over the X-mas period it's 5 faster, which seems odd! I know how to change the time and I belive we ...
6
votes
7answers
3k views

ESXi VM NTP Server

We need to setup an internal NTP server. Because this server will pretty much ONLY be a time server I was thinking of just creating a VM for it. However, Googling around it appears that there there ...
6
votes
3answers
15k views

How to temporarily stop time syncing with domain controller?

I wish to do some testing on my local machine which requires me to put the date forward a year. So I can test some stuff in SQL Server (i've found it not possible to override the sql server time). ...
6
votes
2answers
3k views

Redirecting time.windows.com to internal server

In a corporate environment most machines will be domain joined and therefore get their time from the DCs. However, sometimes you get a machine that isn't in the domain. By default these machines will ...
6
votes
2answers
20k views

date: cannot set date: Operation not permitted [duplicate]

I have received an interesting problem during I tried to set my Server time either with NTD or manually using date command. First of all I have tried to use NTD. I have succesfully installed the ...
6
votes
3answers
10k views

hyper-v server time sync source - PDC / external NTP?

The environement: 10 Hyper-V hosts, all AD joined a lot of VMs AD joined and some not some AD DCs including PDC as Guests What You think is the best approach to time sync a hyper-v farm with AD ...
6
votes
1answer
129 views

Time taken for authentication to work again after changing system time

One of our domain controllers clock drifted way out of sync with the rest of the network (thanks to me forgetting to turn off VMWare's time synchronisation), which caused a whole bunch of servers to ...
6
votes
1answer
1k views

Time too quick in debian, 72 minutes pass in system date in one real world second

Having trouble with system date/time in GNU/Linux/Debian: Time goes too fast for date, time, cron. The sleep command works fine, file modification times are correct. The issue explained via commands: ...
6
votes
2answers
3k views

Synchronize clock with NTP while online, and with RTC while offline?

Is there a existing mechanism that synchronizes a linux system with NTP while online, and with a predictably drifting RTC while offline? We operate remote "collectors": embedded Linux systems that ...
5
votes
4answers
5k views

openwrt: Use rdate with NTP servers?

I've noticed that some embedded devices (such as OpenWRT, which runs on Busybox) use rdate to set the system time, instead of NTP. Rdate is an older time protocol, and I'm having trouble finding any ...
5
votes
3answers
5k views

Allow Facebook access only in specific hours of the day with squid

I've been able to install squid on my Ubuntu Server with basic authentication and everything works perfectly. Recently the boss asked to block facebook access and I did it with no problems. Now it ...
5
votes
4answers
53k views

How to synchronize the clock of a windows server 2003 domain server?

Given a windows server 2003 domain server, I'd like to sync it's time to (any) external time services (it's off a couple of minutes). How to do this 1, manually; 2, in an automated manner every week?
5
votes
2answers
165 views

Reliable Time Protocol Server Online?

I have some OLD legacy hardware that I'd like to keep time synchronized on. It supports the TIME protocol (not NTP). Are there any reliable TIME servers online anymore? If so, where? -M
5
votes
1answer
17k views

Is timesync still required for Windows Server 2012 R2?

Our servers are on a workgroup, we are a small company and do not use a domain controller. In Windows Server 2008 R2 we used TimeSync to help keep the most accurate time, not sure it was really ...
5
votes
3answers
1k views

Clock is 10% faster than normal

I'm having some strange problem with the clock on my server – it's about 10% faster than normal. The problem started 2 days ago and I've not done anything special with the server. I tried to turn of ...
5
votes
3answers
246 views

What is an acceptable secure time source in a datacentre environment?

GPS and NTP are two very typical time sources when accurate clocks are required. However, each has an important failing. NTP does not provide authentication of the time source, and so may be ...