Date

DefaultScheduler 使用 dateChrono。它的時間 schema 接受有效的 Date 物件，因此呼叫排程器前，應先將儲存的字串或時間戳記轉換為 Date。目前的 schema 也會拒絕 new Date(0)（Unix 紀元起點）和無效日期。

在排程器 config 頂層設定 fractionalDays（預設 false）。直接呼叫時需傳入 dateChrono.create({ config: { fractionalDays: false } })。設為 false 時，同一 UTC 日期內的時間差為零，23:00 到次日 01:00 的日期差為一天；設為 true 時，這兩小時得到 2 / 24 天。add(from, 0.5) 始終增加十二小時。精確比較先後請使用 compare。

normalize 如何參與排程

normalize 將 card 或 revlog 的欄位轉換為 { previous, current }。對於 Date 和 Temporal 預設：

複習時，normalize 回傳 previous: card.lastReviewAt 和 current: card.dueAt。
經過天數為 difference(previous ?? current, now)；New 卡片始終為零。
新 card 保存 dueAt: add(now, interval) 和 lastReviewAt: now。
revlog 保存複習前 card 的 dueAt、lastReviewAt，以及本次複習的 reviewTime: now。
撤銷時，normalize 回傳 previous: revlog.lastReviewAt 和 current: revlog.dueAt，用於還原複習前 card 的時間欄位；New 卡片還原為 lastReviewAt: null。

執行預設

import { const dateChrono: Chrono<{
    readonly time: SRSSchema<{
        input: Date;
        output: Date;
    }>;
    readonly config: SRSSchema<{
        input: {
            readonly fractionalDays?: boolean | undefined;
        };
        output: {
            readonly fractionalDays: boolean;
        };
    }>;
    readonly fields: {
        readonly card: SRSSchema<{
            input: {
                dueAt: Date;
                lastReviewAt?: (Date | null) | undefined;
            };
            output: {
                dueAt: Date;
                lastReviewAt: Date | null;
            };
        }>;
        readonly revlog: SRSSchema<{
            input: {
                dueAt: Date;
                lastReviewAt?: (Date | null) | undefined;
                reviewTime: Date;
            };
            output: {
                dueAt: Date;
                lastReviewAt: Date | null;
                reviewTime: Date;
            };
        }>;
    };
}>
dateChrono } from 'ts-fsrs'

const const clock: ChronoCore<Date>clock = const dateChrono: Chrono<{
    readonly time: SRSSchema<{
        input: Date;
        output: Date;
    }>;
    readonly config: SRSSchema<{
        input: {
            readonly fractionalDays?: boolean | undefined;
        };
        output: {
            readonly fractionalDays: boolean;
        };
    }>;
    readonly fields: {
        readonly card: SRSSchema<{
            input: {
                dueAt: Date;
                lastReviewAt?: (Date | null) | undefined;
            };
            output: {
                dueAt: Date;
                lastReviewAt: Date | null;
            };
        }>;
        readonly revlog: SRSSchema<{
            input: {
                dueAt: Date;
                lastReviewAt?: (Date | null) | undefined;
                reviewTime: Date;
            };
            output: {
                dueAt: Date;
                lastReviewAt: Date | null;
                reviewTime: Date;
            };
        }>;
    };
}>
dateChrono.Chrono<{ readonly time: SRSSchema<{ input: Date; output: Date; }>; readonly config: SRSSchema<{ input: { readonly fractionalDays?: boolean | undefined; }; output: { readonly fractionalDays: boolean; }; }>; readonly fields: { readonly card: SRSSchema<{ input: { dueAt: Date; lastReviewAt?: (Date | null) | undefined; }; output: { dueAt: Date; lastReviewAt: Date | null; }; }>; readonly revlog: SRSSchema<{ input: { dueAt: Date; lastReviewAt?: (Date | null) | undefined; reviewTime: Date; }; output: { dueAt: Date; lastReviewAt: Date | null; reviewTime: Date; }; }>; }; }>.create: (ctx: {
    readonly config: {
        readonly fractionalDays: boolean;
    };
}) => ChronoCore<Date>
create({ config: { fractionalDays: false } })
const from = new Date('2026-01-01T23:00:00.000Z')
const to = new Date('2026-01-02T01:00:00.000Z')

console.log(
  JSON.stringify({
    elapsedDays: const clock: ChronoCore<Date>clock.ChronoCore<Date>.difference: (from: Date, to: Date) => numberReturns the distance from the previous review time to the current time.difference(from, to),
    halfDayLater: const clock: ChronoCore<Date>clock.ChronoCore<Date>.add: (from: Date, days: number) => Dateadd(from, 0.5).toISOString(),
    order: const clock: ChronoCore<Date>clock.ChronoCore<Date>.compare?: ((left: Date, right: Date) => number) | undefinedCompares two time values in chronological order.
Returns a negative number when left is earlier than right, zero when
they are equal, and a positive number when left is later than right.
Callers decide how to compare values when a chronology omits this method.compare?.(from, to),
  })
)

跨過午夜時，UTC 日期差為一天；增加半天則讓時間往後移動十二小時。

#Date

#normalize 如何參與排程

#執行預設

Date

normalize 如何參與排程

執行預設