/**
 * D3 Time Format Polyfill - Lightweight date formatting and parsing.
 *
 * This is a drop-in replacement for d3-time-format, implementing only the methods
 * used in the Vega chart rendering system: timeFormat and timeParse.
 *
 * @see VD-5022 - [Zero Dependencies] remove d3 dependency
 */
/**
 * Creates a date formatter function for the given specifier.
 * Mimics d3.timeFormat().
 *
 * Supported directives: %Y, %m, %d, %H, %I, %M, %S, %L, %b, %B, %a, %p, %%
 *
 * @param {string} specifier - Format specifier string (e.g., '%Y-%m-%d', '.%L', ':%S').
 * @returns {Function} A function that formats a Date into a string.
 */
export declare function timeFormat(specifier: string): (date: Date) => string;
/**
 * Creates a date parser function for the given specifier.
 * Mimics d3.timeParse().
 *
 * Supported directives: %Y, %m, %d, %H, %I, %M, %S, %L
 *
 * @param {string} specifier - Parse specifier string (e.g., '%Y-%m-%d').
 * @returns {Function} A function that parses a string into a Date, or null on failure.
 */
export declare function timeParse(specifier: string): (dateString: string) => Date | null;
