Function getUnit

docs/app/js/sanddance-app.js:111295–111298

(f, inv, step, phase)

    };
}
function getUnit(f, inv, step, phase) {
    const u = step <= 1 ? f : phase ? (d, y)=>phase + step * Math.floor((f(d, y) - phase) / step) : (d, y)=>step * Math.floor(f(d, y) / step);
    return inv ? (d, y)=>inv(u(d, y), y) : u;
} // returns the day of the year based on week number, day of week,
// and the day of the week for the first day of the year
function weekday(week1, day, firstDay) {
    return day + week1 * 7 - (firstDay + 6) % 7;