Calculating 6 weeks from April 11 means adding 42 days to the starting date, which results in May 23.
Because April has 30 days, the period from April 11 to April 30 is 19 days, leaving 23 days to continue into May. The remaining 23 days land on May 23. This kind of date arithmetic is useful for project planning, content calendars, event scheduling, and setting deadlines. The following sections explain how to perform this calculation manually, how to verify it automatically, and how to handle edge cases like leap years or different starting dates.