AnyLogic supports all popular time units: milliseconds, seconds, minutes, hours, days, weeks, months. years. You may change the model time units whenever you like, though we advise that you select the model time units when you create the model.To set time units
However, months and years do not have fixed duration (month may be 28, 29, 30, 31 day, year may be 365 or 366 days, etc). If you choose month here, we assume that month is always is 30 days long. The same situation with a year: we assume that it is always 365 days long.