SmarterClock

Used to ensure the time used is in sync across distributed systems. The sync is achived by the following process:

• Fetches the time from an NTP server.
• Adjusts for network latency and transfer time
• Computes the delta between the NTP server and the system clock and stores the delta for later use.
• Uses all the stored deltas to get the average time drift from UTC.

Getting Started

Install the module.

npm install @smarterservices/smarterclock
```	

Import the module into your codebase

```javascript
var smarterclock = require('@smarterservices/smarterclock')
```	

Create an instance of the clock object passing in the required params. See the options section below for options that can be used.

```javascript
var options = {};

// create a new instance
var clock = new smarterclock(options);

// get the current unix timestamp
var currentTime = clock.getTime();

console.log(currentTime);

Options

The clock constructor can accept the following options. all options are optional

• syncDelay (number) : The time (in seconds) between each call to an NTP server to get the latest UTC timestamp. Defaults to 300 (which is 5 minutes).
• history (number): The nubmer of delta values that should be maintained and used for calculating your local time drift. Defaults to 10.
• servers (array) : An array of NTP servers to use when looking up time. Each value in the array should be an object with the keys server and port. Defaults to pool.ntp.org.

Example

{
    "syncDelay" : 60,
    "history": 10,
    "servers" : [{"server": "pool.ntp.org", "port": 123}]
}
```	

    
## Methods

###getTime()

Returns unix timestamp based on delta values between server and your local time. This is the time that can be used instead of ```new Date().getTime()```
    
#### Example	

```javascript
clock.getTime();
```	
    
    

###syncTime()

An on-demand method that will force a sync with an NTP server.

```javascript
clock.syncTime();
```