How to Update Date and Time of Raspberry Pi With out Internet

Question

I have connect my Raspberry Pi to LAN but there is no internet available. Is there any method to update raspberry pi date time by using a PC (windows 7) in LAN? I want to get computer date and time to my Raspberry Pi when it is booting.

Answer 1

Remember that Raspberry Pi does not have real time clock. So even you are connected to internet have to set the time every time you power on or restart.

This is how it works:

1. Type sudo raspi-config in the Raspberry Pi command line
2. Internationalization options
3. Change Time Zone
4. Select geographical area
5. Select city or region
6. Reboot your pi

Next thing you can set time using this command

sudo date -s "Mon Aug  12 20:14:11 UTC 2014" 

More about data and time

man date 

When Pi is connected to computer should have to manually set data and time

Answer 2

Thanks for the replies.
What I did was,
1. I install meinberg ntp software application on windows 7 pc. (softros ntp server is also possible.)
2. change raspberry pi ntp.conf file (for auto update date and time)

server xxx.xxx.xxx.xxx iburst server 1.debian.pool.ntp.org iburst server 2.debian.pool.ntp.org iburst server 3.debian.pool.ntp.org iburst 

3. If you want to make sure that date and time update at startup run this python script in rpi,

import os  try:     client = ntplib.NTPClient()     response = client.request('xxx.xxx.xxx.xxx', version=4)     print "===================================="     print "Offset : "+str(response.offset)     print "Version : "+str(response.version)     print "Date Time : "+str(ctime(response.tx_time))     print "Leap : "+str(ntplib.leap_to_text(response.leap))     print "Root Delay : "+str(response.root_delay)     print "Ref Id : "+str(ntplib.ref_id_to_text(response.ref_id))     os.system("sudo date -s '"+str(ctime(response.tx_time))+"'")     print "====================================" except:     os.system("sudo date")     print "NTP Server Down Date Time NOT Set At The Startup"     pass 

I found more info in raspberry pi forum.