二つの日付間の差分を計算し、日付の計算。
Time Travel is a date calculator that allows you to calculate the differences between two dates in days, weeks months or years. You can calculate dates retroactive (e.g how many days since you were born, how many days you have worked etc.) or input the number of days, weeks or months to figure out the corresponding date in the future. You can find out the day of year. Simple interface, easy to use.