RocketChat/Rocket.Chat

import { useUserPreference, useSetting } from '@rocket.chat/ui-contexts';
import moment from 'moment';
import { useCallback } from 'react';

const dayFormat = ['h:mm A', 'H:mm'] as const;

export const useFormatTime = (): ((input: moment.MomentInput) => string) => {
    const clockMode = useUserPreference<1 | 2>('clockMode');
    const format = useSetting('Message_TimeFormat') as string;
    const sameDay = clockMode !== undefined ? dayFormat[clockMode - 1] : format;

    return useCallback(
        (time) => {
            switch (clockMode) {
                case 1:
                case 2:
                    return moment(time).format(sameDay);

                default:
                    return moment(time).format(format);
            }
        },
        [clockMode, format, sameDay],
    );
};