microsoft/playwright · error · Error

Invalid date: ${epoch}

Error message

Invalid date: ${epoch}

What it means

Thrown by parseTime in clock.ts:153. new Date(epoch).getTime() returned NaN (non-finite), so the epoch value passed to clock.install / setFixedTime / setTime could not be interpreted as a date.

Source

Thrown at packages/playwright-core/src/server/clock.ts:153

    );
  }

  while (i--) {
    parsed = parseInt(strings[i], 10);
    if (parsed >= 60)
      throw new Error(`Invalid time ${str}`);
    ms += parsed * Math.pow(60, l - i - 1);
  }

  return ms * 1000;
}

function parseTime(epoch: string | number | undefined): number {
  if (!epoch)
    return 0;
  const parsed = new Date(epoch);
  if (!isFinite(parsed.getTime()))
    throw new Error(`Invalid date: ${epoch}`);
  return typeof epoch === 'number' ? epoch : parsed.getTime();
}

View on GitHub (pinned to c8fc3bf8d3)

Solutions

1. Pass a valid epoch number (milliseconds) or a Date-parseable ISO string.
2. Construct the value via new Date(...).getTime() and confirm isFinite before passing.
3. Use Date.now() for 'current time' installs.

Example fix

// before
await page.clock.setFixedTime('noon');
// after
await page.clock.setFixedTime(new Date('2024-01-01T12:00:00Z').getTime());

// Validate the epoch before installing the clock.
function toEpoch(v: number | string): number {
  const ms = typeof v === 'number' ? v : new Date(v).getTime();
  if (!Number.isFinite(ms)) throw new Error(`Invalid date for clock: ${v}`);
  return ms;
}
await page.clock.setFixedTime(toEpoch(input));

When it happens

Trigger: clock.setFixedTime('foo'); clock.setTime('2024-13-40'); clock.setFixedTime(NaN); an out-of-range or unparseable date string.

Common situations: User-typed date strings; locale-formatted dates the Date constructor rejects; passing undefined fields through to the clock.

Related errors

• Invalid date: ${time}
• Clock only understands numbers, 'mm:ss' and 'hh:mm:ss'
• Invalid time ${str}
• Invalid input image
• Invalid output dimensions

AI-assisted analysis of microsoft/playwright@c8fc3bf8d3 (2026-08-12). Data as JSON: /api/errors/d4927dfd70bbcfdf. Report an issue: GitHub.