Add and subtract months and years, calculate year dates. Here you can find out, which month was or will be in a certain number of months and which year was or will be in a certain number of years. For years in the past, the year 0 didn't exist, so before the year 1, there came 1 BCE (Before Common Era). Subtracting, minus, is done with the word Before, adding, plus, with In. Please enter one field in a row and click Calculate.
Different months vary in length, between 28 and 31 days, but this is ignored in such a calculation. In everyday language, people often say something like a month ago or in a month. In this case, it can be assumed that it doesn't have to be particularly precise and that individual days don't count. With some restrictions, this is also true for years, although there are only normal years with 365 days and leap years with 366 days. In addition, a year is of course 12 times as long as an average month, which is why a day's difference in a year makes a much smaller percentual difference than in a month. If you want to know the date in or before a certain period of time more precisely, or without these inaccuracies, you can use the time and date calculator.