timrwood/moment — Issue #78: Adding across DST results in a difference of an hour
Author: rockymeza
Created: 2011-11-21 18:26:15+00:00
State: open

```js
// create a date outside of Daylight Savings Time
var m = moment(new Date(2011, 0, 1, 0, 0, 0));
m.format('h:mm a');
// 12:00 am

// change it to a date inside Daylight Savings Time
m.add('weeks', 20);
m.format('h:mm a');
// 1:00 am
```

If we cross the DST line by adding days, the bug also occurs
```js
// the day before DST in the US
var m = moment(new Date(2011, 2, 12, 5, 0, 0));
m.format('h:mm a');
// 5:00 am

// DST day in the US
m.add('days', 1);
m.format('h:mm a');
// 6:00 am
```