DateTime - Manipulation Extensions

Simplified methods for adding/subtracting days, months, and years, plus a critical utility for calculating future business days.

1. 🗓️ Simple Duration

   addDays(int days) · DateTime

   days · int · required

   The number of days to add to the current date.

   Adds a number of days to the current DateTime object.

   final futureDate = DateTime.now().addDays(5);
   

   subtractDays(int days) · DateTime

   days · int · required

   The number of days to subtract from the current date.

   Subtracts a number of days from the current DateTime object.

   final pastDate = DateTime.now().subtractDays(10);
   
2. 📅 Calendar Components (Use with Caution)

   Be cautious with addMonths and addYears. Dart’s DateTime constructor handles invalid days (like Feb 30th) by overflowing to the next month/year. Always test edge cases (e.g., Jan 31st + 1 month = Mar 3rd).

   addMonths(int months) · DateTime

   months · int · required

   The number of months to add to the current date.

   Adds a number of months. (Warning: Susceptible to date overflow errors.)

   // Goes from March 15th to June 15th
   final newDate = DateTime(2025, 3, 15).addMonths(3);
   

   subtractMonths(int months) · DateTime

   months · int · required

   The number of months to subtract from the current date.

   Subtracts a number of months. (Warning: Susceptible to date overflow errors.)

   // Goes from May 20th to February 20th
   final pastDate = DateTime(2025, 5, 20).subtractMonths(3);
   

   addYears(int years) · DateTime

   years · int · required

   The number of years to add to the current date.

   Adds a number of years. (Warning: Be mindful of leap years.)

   final futureYear = DateTime.now().addYears(5);
   

   subtractYears(int years) · DateTime

   years · int · required

   The number of years to subtract from the current date.

   Subtracts a number of years. (Warning: Be mindful of leap years.)

   final pastYear = DateTime.now().subtractYears(2);
   
3. 💼 Business Days

   addBusinessDays(int days) · DateTime

   days · int · required

   The number of business days to add.

   Adds a number of business days (Monday to Friday) to the current date, automatically skipping weekends.

   // If today is Friday, adding 1 business day results in Monday.
   final nextWorkDay = DateTime(2025, 11, 28).addBusinessDays(1);