Get the Month and Year X number of months from now

Question

I am attempting to generate a PageView that will display the Month and Year related to the number of times you swipe in either directon.

Example 1:

I swipe right twice, so I get Feb 2021

Example 2:

I swipe left 12 times, so I get April 2020

I have attempted to create a DateTime.now() and subtract an integer of months, but I'm not having much luck. I have looked at various plugins like DateUtils, but again no luck.

I have been at what should be a simple solution for while now and would appreciate a guidance.

The closet I get is the following which requires me to know the days in each month which isn't ideal

(DateTime.now().subtract(Duration(days: 90)).toString())

Solution

From DataTime docunamtion:

Returns a new [DateTime] instance with [duration] added to [this].

var today = DateTime.now();

var fiftyDaysFromNow = today.add(const Duration(days: 50));

// adds 1 days

DateTime _future = DateTime.now().add(const Duration(days: 1));

//substracts 1 day
DateTime _tomorrow2 = DateTime.now().subtract(const Duration(days: 1));

Also this, credit ,define the base time, let us say:

var date = new DateTime(2018, 1, 13);

Now, you want the new date:

var newDate = new DateTime(date.year, date.month - 1, date.day);

And you will get

2017-12-13

Comments

[Yonkee]

Thanks, but I need to increment or decrement by months, not days.

[Huthaifa Muayyad]

check my modified answer :)

[Huthaifa Muayyad]

You're most welcome, kindly consider marking at we an answer if it solved your question :)

[jamesdlin]

Blindly incrementing or decrementing date.month won't work if date.day isn't valid for that month.

[Huthaifa Muayyad]

He's not interested in days, but month and year. Also, days can be accounted for easily. Scope of the question was how to subtract months besides using i increments of 30

[Randal Schwartz]

And here's a video that goes into this with more detail: Proper Month and Day Arithmetic in Dart and Flutter: youtu.be/LpoBYgzKVwU

[Randal Schwartz]

And this breaks down if we're looking at the 30th or 31st day of the month. See my video at "Proper Month and Day Arithmetic in Dart and Flutter: youtu.be/LpoBYgzKVwU" for details.