/**
 * Format bigint TIME microseconds as HH:MM:SS.mmm, adding the microsecond
 * digits only when the value has sub-millisecond precision.
 */
export declare function timeFromMicros(value: bigint): string;
export interface TimestampStringParts {
    date: string;
    time?: string;
    fraction?: string;
    /** `Z` or a `+HH:MM` / `-HH:MM` offset. */
    offset?: string;
}
/**
 * Split an ISO-like timestamp string (`YYYY-MM-DD[( |T)HH:MM[:SS[.f]]][offset]`)
 * into its parts. Offsets may be `Z`, `+HH`, `+HHMM` or `+HH:MM`.
 */
export declare function parseTimestampString(value: string): TimestampStringParts | undefined;
/**
 * Build a string that `new Date()` parses, treating a missing offset as UTC.
 * Strings outside the ISO-like shape keep the older best effort handling.
 */
export declare function timestampStringToDateInput(value: string, parts?: TimestampStringParts | undefined): string;
/**
 * Rewrite parsed timestamp parts as a UTC wall time (`YYYY-MM-DD HH:MM:SS`
 * plus the original fractional digits, without an offset). A missing offset
 * is read as UTC. Offsets are whole minutes, so the fraction is unchanged.
 */
export declare function utcTimestampString(parts: TimestampStringParts): string | undefined;
/**
 * Format microseconds since the Unix epoch the way DuckDB prints a
 * TIMESTAMP: trailing fractional zeros are trimmed. `withTimezone` appends
 * `+00` because the value is rendered in UTC.
 */
export declare function timestampStringFromMicros(micros: bigint, withTimezone: boolean): string;
/**
 * Format INTERVAL parts the way DuckDB casts an INTERVAL to VARCHAR, for
 * example `1 year 2 months 3 days 04:05:06.5`. DuckDB parses this text back.
 */
export declare function intervalToString(months: number, days: number, micros: bigint): string;
/** Sub-millisecond microseconds carried by a fractional seconds string. */
export declare function subMillisecondMicros(fraction: string | undefined): bigint;