Soenneker.Cron.Builder 4.0.359

Soenneker.Cron.Builder

A mutable fluent builder for five-field cron expressions, with optional leading seconds for six-field schedulers.

Installation

dotnet add package Soenneker.Cron.Builder

Common schedules

Construct a new builder for each expression; no dependency-injection registration is required.

using Soenneker.Cron.Builder;
using Soenneker.Enums.DayOfWeek;

string everyFiveMinutes = new CronBuilder()
    .WithMinuteInterval(5)
    .Build();
// */5 * * * *

string weekdayMorning = new CronBuilder()
    .Daily(hour: 9, minute: 30)
    .Weekdays()
    .Build();
// 30 9 * * MON-FRI

string mondayAtNoon = new CronBuilder()
    .Weekly(DayOfWeekType.Monday, hour: 12)
    .Build();
// 0 12 * * MON

string firstOfMonth = new CronBuilder()
    .Monthly(dayOfMonth: 1, hour: 2, minute: 15)
    .Build();
// 15 2 1 * *

ToString() returns the same value as Build().

Field order and defaults

Without WithSeconds, output uses the conventional order:

minute hour day-of-month month day-of-week

The untouched builder produces 0 * * * *, which means the top of every hour. Minutely() changes the minute field to *; Hourly() sets minute to 0 and hour to *.

Calling WithSeconds adds a leading seconds field:

string expression = new CronBuilder()
    .WithSeconds(30)
    .Minutely()
    .Build();
// 30 * * * * *

Six-field cron dialects are not universal. Confirm that the target scheduler interprets the first field as seconds before using this form.

Composition rules

Builder calls update individual fields; they do not reset unrelated fields. This allows combinations such as Daily(...).Weekdays(), but reusing a builder also retains earlier month or day restrictions. Create a new builder when starting a different schedule.

Numeric ranges are checked for seconds, minutes, hours, day of month, month, and interval methods. Build() rejects a fixed day of month combined with any day-of-week restriction because that combination has scheduler-dependent semantics.

OnDayOfWeek(string) uppercases and emits the supplied token unchanged. Use it only for syntax supported by the target scheduler; the builder does not validate raw expressions.

The builder only formats expressions. It does not evaluate schedules, apply a time zone, account for daylight-saving transitions, or register jobs with a scheduler. Instances are mutable and should not be shared across concurrent expression construction.