Time Formatting

This example demonstrates how to customize timestamp formatting and timezones. Logly allows you to use standard date format strings or switch between Local and UTC time.

Code Example

const std = @import("std");
const logly = @import("logly");

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    // Enable colors on Windows
    _ = logly.Terminal.enableAnsiColors();

    const logger = try logly.Logger.init(allocator);
    defer logger.deinit();

    var config = logly.Config.default();

    // Example 1: Default format (YYYY-MM-DD HH:mm:ss.SSS)
    logger.configure(config);
    try logger.info("Default time format", @src());

    // Example 2: Custom time format
    // Supports standard format specifiers
    config.time_format = "HH:mm:ss";
    logger.configure(config);
    try logger.info("Short time format", @src());

    // Example 3: UTC timezone
    // Switch to UTC time instead of local time
    config.timezone = .utc;
    config.time_format = logly.Config.TimeFormat.iso8601;
    logger.configure(config);
    try logger.info("UTC time", @src());

    // Example 4: Local timezone offset in custom format (+HH:MM)
    config.timezone = .local;
    config.time_format = "YYYY-MM-DD HH:mm:ss ZZZ";
    logger.configure(config);
    try logger.info("Local timezone offset (ZZZ)", @src());

    // Example 5: Local timezone compact offset (+HHMM)
    config.time_format = "YYYY-MM-DD HH:mm:ss ZZ";
    logger.configure(config);
    try logger.info("Local timezone compact offset (ZZ)", @src());
}

ZZZ and ZZ are useful in production when logs from multiple regions are aggregated, because each event keeps an explicit timezone offset.

Expected Output

[2024-06-01 12:00:00] [INFO] Default time format
[12:00:00] [INFO] Short time format
[10:00:00] [INFO] UTC time
[2024-06-01 12:00:00 +02:00] [INFO] Local timezone offset (ZZZ)
[2024-06-01 12:00:00 +0200] [INFO] Local timezone compact offset (ZZ)