How Long is Allah's Day?

1,000 years. 50,000 years.
A Day with Allah is as a thousand years of what ye reckon.
He directeth the ordinance from the heaven unto the earth; then it ascendeth unto Him in a Day, whereof the measure is a thousand years of that ye reckon.
Unto Him in a Day whereof the span is fifty thousand years.
In general, a day with Allah equals a thousand years of our years. The fifty thousand years mentioned in the other verse is the length of the day of judgment.