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

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.

Answer 2

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'})