monline

"Imagine you have made a world tour in August 2009 (summer time!) and you have used your digital photo camera to create pictures, videos and voice recordings.

In this guide I will not refer to these items by their specific characteristics (photo, video, audio), but simply regard all of them as "files." Secondly, we assume that the files are saved on a storage medium, which is very likely formatted as FAT (as specified in the DCIM standard for digital cameras).

You have created three files in America/Los Angeles (UTC-0700), three files in your hometown Europe/Vienna (UTC+0200) and three files in Asia/Bangkok (UTC+0700), and at the end of the summer, you return to your hometown Europe/Vienna.

This guide shows you how to correctly bring your files' timestamps from a local time zone-based file system (such as your external flash drive, formatted as FAT32) to a file system using coordinated universal time (UTC) (such as your internal hard disk, formatted as HFS+) using the Finder on MacOS X."

Actually this guide is relevant not only for Mac OS X users, but everybody involved with files that have dates from a number of timezones. The same steps should be followed by Windows (etc.) users as well.

By default Ubuntu contains only ntpdate for time synchronization and updates the system clock from ntp.ubuntu.com only when the network interface is raised up (check the file /etc/network/if-up.d/ntpdate). In a LAN you should set up a local NTP server and use that for syncing workstations.