Crate shift_algorithm 

shift-algorithm

Core shift scheduling algorithm. The foundation of the entire 班伴 (ShiftMate) project.

Given any date, this crate determines what shift a worker is on, based on a repeating cycle shared across multiple teams.

How it works

The default cycle is 42 days, shared by 6 teams (一值～六值):

早 早 中 中 休 夜 夜  休 休 早 早 中 中 休  夜 休 休 休 早 早 中 休
夜 夜 休 休 休 早 中 中  休 夜 夜 休 休 学 学 学 学 学 休 休

Each team is offset by 7 days (42 / 6). Reference date 2025-12-15 is day 1. Team 1 starts at offset 0, team 2 at offset 7, etc.

Quick start

use shift_algorithm::cycle::default_config;
use shift_algorithm::get_shift_info;
use chrono::NaiveDate;

let config = default_config();
let today = NaiveDate::from_ymd_opt(2026, 5, 22).unwrap();
let info = get_shift_info(today, &config, 0);

println!("{:?} · day {}/{}",
    info.shift_type,
    info.day_of_cycle,
    config.cycle_length,
);

Crate structure

• types — ShiftType enum, ShiftInfo struct, ShiftCycleConfig
• cycle — Default constants (42-day cycle, reference date, 6 teams)
• calculator — Pure functions: offset, normalize, get shift for date

Re-exports

pub use calculator::*;

pub use cycle::*;

pub use types::*;

Modules

calculator

Core shift calculation functions.

cycle

Default constants and the standard 42-day shift cycle.

types

Core data types for the shift scheduling system.