zoneinfoformaatissa

The zoneinfo format is a simple text file format used to store timezone information. These files are commonly found on Unix-like operating systems and are part of the tz database, also known as the IANA Time Zone Database. The purpose of the zoneinfo format is to define the rules for daylight saving time and standard time transitions for specific geographical regions.

Each zoneinfo file typically begins with a header section that specifies general information about the timezone, such as its name and abbreviation. Following the header are lines that define the historical and future rules for that timezone. These rules specify the date and time when a timezone transition occurs, the offset from Coordinated Universal Time (UTC) during standard time, and the offset from UTC during daylight saving time.

The format uses a series of keywords and values to represent these rules. For example, a line might indicate a rule change occurring on a specific date, the offset from UTC, and the abbreviation for the new timezone. The zoneinfo format is designed to be human-readable, making it relatively straightforward to understand and edit. However, due to the complexity of timezone rules, manual editing can be prone to errors.

Software applications that require accurate timekeeping, such as operating systems, web servers, and programming language runtimes, rely on these zoneinfo files to correctly interpret and display local times. The tz database is regularly updated to reflect changes in timezone legislation and historical corrections, ensuring that systems using zoneinfo files maintain accurate time representations.