bash Cookbook

Handling Time Zones, Daylight Saving Time, and Leap Years

Problem

You need to account for time zones, Daylight Saving Time, and leap years or seconds.

Solution

Don’t. This is a lot trickier than it sounds. Leave it to code that’s already been in use and debugged for years, and just use a tool that can handle your needs. Odds are high that one of the other recipes in this chapter has covered what you need, probably using GNU date. If not, there is almost certainly another tool out there that can do the job. For example, there are a number of excellent Perl modules that deal with dates and times.

Really, we aren’t kidding. This is a real nightmare to get right. Save yourself a lot of agony and just use a tool.

See Also

• Formatting Dates for Display

• Automating Date Ranges

• Converting Dates and Times to Epoch Seconds

• Converting Epoch Seconds to Dates and Times

• Figuring Out Date and Time Arithmetic