/**
 * A utility class for managing time-related operations and measurements.
 * Provides functionality to track process timing, system uptime, and frame intervals.
 *
 * @example
 * ```typescript
 * // Get current system uptime
 * const uptime = Time.timeFromSystemStart;
 *
 * // Get last frame duration
 * const frameTime = Time.lastTickTimeInterval;
 * ```
 */
export declare class Time {
    private static __currentProcessBeginTime;
    private static __lastProcessBeginTime;
    private static __lastProcessEndTime;
    private static __lastTickTimeInterval;
    private static __systemStartTime;
    private static __intervalProcessBegin;
    /**
     * Marks the beginning of a process cycle and updates timing measurements.
     * This method should be called at the start of each frame or processing cycle.
     *
     * @internal
     * @remarks
     * This method updates the current process begin time, calculates the interval
     * since the last process began, and initializes the system start time if needed.
     */
    static _processBegin(): void;
    /**
     * Marks the end of a process cycle and calculates the processing duration.
     * This method should be called at the end of each frame or processing cycle.
     *
     * @internal
     * @remarks
     * This method records the process end time and calculates the duration
     * of the current processing cycle (tick time interval).
     */
    static _processEnd(): void;
    /**
     * Gets the timestamp when the current process cycle began.
     *
     * @returns The time in milliseconds when the current process began
     * @readonly
     */
    static get timeAtProcessBeginMilliseconds(): number;
    /**
     * Gets the timestamp when the last process cycle ended.
     *
     * @returns The time in milliseconds when the last process ended
     * @readonly
     */
    static get timeAtProcessEndMilliseconds(): number;
    /**
     * Gets the elapsed time since the system started.
     *
     * @returns The elapsed time in seconds since system initialization
     * @readonly
     * @remarks
     * This value represents the total uptime of the system and is useful
     * for animations, timing calculations, and performance measurements.
     */
    static get timeFromSystemStart(): number;
    /**
     * Gets the duration of the last completed processing cycle.
     *
     * @returns The last tick time interval in seconds
     * @readonly
     * @remarks
     * This value represents the frame time or delta time, which is commonly
     * used for frame-rate independent animations and physics calculations.
     */
    static get lastTickTimeInterval(): number;
    /**
     * Gets the time interval between the start of consecutive process cycles.
     *
     * @returns The interval between process beginnings in seconds
     * @readonly
     * @remarks
     * This value indicates the time gap between when consecutive processing
     * cycles started, which can be useful for measuring frame rate consistency.
     */
    static get intervalProcessBegin(): number;
    /**
     * Gets the duration of the last completed processing cycle in milliseconds.
     *
     * @returns The last tick time interval in milliseconds
     * @readonly
     * @remarks
     * This is the millisecond version of {@link lastTickTimeInterval}.
     * Useful when higher precision timing is needed.
     */
    static get lastTimeTimeIntervalInMilliseconds(): number;
}