Thanks! It does this according to doc: This method adds the specified amount to the years field in three steps: * Add the input years to the year fie

Thanks! It does this according to doc: This method adds the specified amount to the years field in three steps: * Add the input years to the year field * Check if the resulting date would be invalid * Adjust the day-of-month to the last valid day if necessary TIL. I didn't know that Java had a builtin calendar (instead of datetime) library.