How can I add timestamp to logs using node.js library Winston?

I was dealing with the same issue myself. There are two ways I was able to do this.

When you include Winston, it usually defaults to adding a Console transport. In order to get timestamps to work in this default case, I needed to either:

1. Remove the console transport and add again with the timestamp option.
2. Create your own Logger object with the timestamp option set to true.

The first:

var winston = require('winston');
winston.remove(winston.transports.Console);
winston.add(winston.transports.Console, {'timestamp':true});

The second, and cleaner option:

var winston = require('winston');
var logger = new (winston.Logger)({
    transports: [
      new (winston.transports.Console)({'timestamp':true})
    ]
});

Some of the other options for Console transport can be found here:

• level: Level of messages that this transport should log (default 'debug').
• silent: Boolean flag indicating whether to suppress output (default false).
• colorize: Boolean flag indicating if we should colorize output (default false).
• timestamp: Boolean flag indicating if we should prepend output with timestamps (default false). If function is specified, its return value will be used instead of timestamps.

You can use built-in util and forever to achieve logging with timestap for your nodejs server. When you start a server add log output as part of the parameter:

forever start -ao log/out.log server.js

And then you can write util in your server.js

server.js

var util = require('util');
util.log("something with timestamp");

The output will look something like this to out.log file:

out.log

15 Mar 15:09:28 - something with timestamp

Although I'm not aware of winston, this is a suggestion. I use log4js for logging & my logs by default look like this

[2012-04-23 16:36:02.965] [INFO] Development - Node Application is running on port 8090
[2012-04-23 16:36:02.966] [FATAL] Development - Connection Terminated to  '127.0.0.1' '6379'

Development is the environment of my node process & [INFO|FATAL] is log level

Maintaining different profiles for logging is possible in log4js. I have Development & Production profiles. Also there are logger types like rolling file appender, console appender, etc. As a addon your log files will be colorful based on the log level [Trace, Info, Debug, Error, Fatal] ;)

log4js will override your console.log It is a configurable parameter now in 0.5+