Convert Year (Julian) (y (Julian)) to Planck Time (tₚ) instantly.
About these units
Year (Julian) (y (Julian))
A Julian year is defined as exactly 365.25 days, reflecting the structure of the Julian calendar introduced by Julius Caesar in 45 BCE. This calendar assumed a fixed year length with a leap year every four years. Although revolutionary in its simplicity, the Julian year overestimates the actual tropical year by about 11 minutes, causing the calendar date to drift slowly relative to the seasons—an issue that accumulated to more than 10 days by the 16th century. Astronomers still use the Julian year as a standardized unit for long-term timekeeping, especially when expressing stellar motions, orbital periods, and cosmological timescales. Its simplicity and fixed length make it ideal for scientific definition even though it is obsolete as a civil calendar.
Planck Time (tₚ)
Planck time is the smallest meaningful unit of time in known physics, defined as the time it takes light to travel one Planck length. It equals approximately 5.39 × 10⁻⁴⁴ seconds. Below the Planck time, current theories of spacetime—General Relativity and Quantum Mechanics—break down, and we enter a regime where quantum gravity dominates. Planck time defines the theoretical boundary of the earliest moments of the universe, immediately after the Big Bang, before classical spacetime emerged. It is not a unit we can measure directly; rather, it represents a fundamental limit set by nature's constants, including the speed of light, the gravitational constant, and Planck's constant. The Planck time is the frontier where physics transitions from the known into the speculative—where time itself may become granular, discontinuous, or fundamentally different from the human conception.