# date-drift

Increase or decrease a Date by year, month, date, hours, minutes, seconds and milliseconds.

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## Install

    $ npm install date-drift

## Usage

```javascript

var DateDrift = require('date-drift');

var df = new DateDrift(new Date('2018-9-30 10:02:04')); // default: new Date();

// support chained calls
var newDate = df.driftYears(-1).driftMonths(2).driftDays(-3).getDate();

console.log(newDate.toISOString()); // output: 2017-11-27T02:02:04.000Z
```

## APIs

Increase/decrease years by driftYears(dYears), dYears must be an integer.

```javascript
df.driftYears(dYears);
```

Increase/decrease months by driftMonths(dMonths), dMonths must be an integer.

```javascript
df.driftMonths(dMonths);
```

Increase/decrease days by driftDays(dDays), dDays must be an integer.

```javascript
df.driftDays(dDays);
```

Increase/decrease hours by driftHours(dHours), dHours must be an integer.

```javascript
df.driftHours(dHours);
```

Increase/decrease minutes by driftMinutes(dMinutes), dMinutes must be an integer.

```javascript
df.driftMinutes(dMinutes);
```

Increase/decrease seconds by driftSeconds(dSeconds), dSeconds must be an integer.

```javascript
df.driftSeconds(dSeconds);
```

Increase/decrease milliseconds by driftMilliseconds(dMilliseconds), dMilliseconds must be an integer.

```javascript
df.driftMilliseconds(dMilliseconds);
```

Get javascript Date instance.

```javascript
df.getDate(); // return a Date instance.
```

## Test
To run the test suite, first install the dependencies, then run npm test:
    
    $ npm install
    $ npm test