Sugar - Standard Library Extension

Sugar is an extension to Dart's standard library.

It provides the following (and much more!):

• Date-time and timezone API inspired by java.time.
• Monads such as Result<S,F>.
• Syntax sugar for aggregating & manipulating collections.
• Types for representing and working with ranges & intervals.

It consolidates several micro-packages that provide bits and pieces of date-time & timezone utilities into a single package.

Why Sugar's date-time API over other packages?

• Sugar is able to detect the platform's timezone, ZonedDateTime.now() synchronously. Other packages such as timezone don't. flutter_native_timezone detects the timezone asynchronously while DateTime.timeZoneName returns an ambiguous abbreviation that can refer to multiple timezones. Sugar provide a TZDB timezone identifier such as Asia/Singapore. See List of timezone abbreviations.

• Sugar is less hassle to set up. You don't need to fiddle with assets. Simply create a ZonedDateTime.

• Sugar has (in theory) lower initialization cost. Other packages often parse the timezone information from binary files at runtime. We rely on code generation to eliminate IO during initialization completely.

• Sugar has a better memory footprint. Other packages often load the entire TZ database into memory. We rely on lazy initialization to load only timezones actually used.

• Sugar offers more than just ZonedDateTime. It aims to be a one-stop for your date-time needs. It offers classes such as LocalTime & Period, and utilities such as retrieving the ordinal week of the year.

Getting Started

Run the following command:

dart pub add sugar

Alternatively, add Sugar as a dependency in your pubspec:

dependencies:
  sugar: ^4.0.0

Import the library:

import 'package:sugar/sugar.dart';

Check out the documentation to get started.

Updating timezones

This section is for maintainers. It describes how to update the embedded IANA database. It assumes that you are on macOS/Linux. The current version of the IANA database is 2025a.

$ chmod +x tool/refresh.sh
$ tool/refresh.sh