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

Question

I want to add timestamp to logs. What is the best way to achieve this?

Answer 1

Above answers did not work for me. In case you are trying to add timestamp to your logs using the latest version of Winston - 3.0.0-rc1, this worked like charm:

    const {transports, createLogger, format} = require('winston');

    const logger = createLogger({
        format: format.combine(
            format.timestamp(),
            format.json()
        ),
        transports: [
            new transports.Console(),
            new transports.File({filename: 'logs/error/error.log', level: 'error'}),
            new transports.File({filename: 'logs/activity/activity.log', level:'info'})
        ]
    });

I used 'format.combine()'. Since I needed timestamp on all my transports, I added the formatting option within the createLogger, rather than inside each transport. My output on console and on file (activity.log) are as follows:

{"message":"Connected to mongodb","level":"info","timestamp":"2018-02-01T22:35:27.758Z"}
{"message":"Connected to mongodb","level":"info","timestamp":"2018-02-01T22:35:27.758Z"}

We can add formatting to this timestamp in 'format.combine()' as usual using:

format.timestamp({format:'MM-YY-DD'})