/**
 * All date units supported by date-vir. These are the singular versions of {@link DurationUnit}.
 *
 * @category Unit
 */
export declare enum DateUnit {
    Year = "year",
    Quarter = "quarter",
    Month = "month",
    Week = "week",
    Day = "day",
    Hour = "hour",
    Minute = "minute",
    Second = "second",
    Millisecond = "millisecond"
}
/**
 * All {@link DateUnit} values that are zero indexed (start at 0, like seconds).
 *
 * @category Internal
 */
export declare const zeroIndexedDateUnits: readonly [DateUnit.Year, DateUnit.Hour, DateUnit.Minute, DateUnit.Second, DateUnit.Millisecond];
/**
 * All {@link DateUnit} values that are one indexed (start at 1, like days of a month).
 *
 * @category Internal
 */
export declare const oneIndexedDateUnits: readonly [DateUnit.Quarter, DateUnit.Month, DateUnit.Week, DateUnit.Day];
/**
 * All {@link DateUnit} values in an array ordered from smallest to largest.
 *
 * @category Internal
 */
export declare const orderedDateUnit: readonly [DateUnit.Millisecond, DateUnit.Second, DateUnit.Minute, DateUnit.Hour, DateUnit.Day, DateUnit.Week, DateUnit.Month, DateUnit.Quarter, DateUnit.Year];
/**
 * All valid quarter numbers (1-4).
 *
 * @category Unit
 */
export type Quarter = 1 | 2 | 3 | 4;