Format the relative date

Write a function formatDate(date) that should format date as follows:

If since date passed less than 1 second, then "right now".
Otherwise, if since date passed less than 1 minute, then "n sec. ago".
Otherwise, if less than an hour, then "m min. ago".
Otherwise, the full date in the format "DD.MM.YY HH:mm". That is: "day.month.year hours:minutes", all in 2-digit format, e.g. 31.12.16 10:00.

For instance:

 alert( formatDate(new Date(new Date - 1)) ); // "right now" alert( formatDate(new Date(new Date - 30 * 1000)) ); // "30 sec. ago" alert( formatDate(new Date(new Date - 5 * 60 * 1000)) ); // "5 min. ago" // yesterday's date like 31.12.16 20:00 alert( formatDate(new Date(new Date - 86400 * 1000)) ); 

Open a sandbox with tests.

To get the time from date till now – let’s substract the dates.

function formatDate(date) { let diff = new Date() - date; // the difference in milliseconds if (diff < 1000) { // less than 1 second return 'right now'; } let sec = Math.floor(diff / 1000); // convert diff to seconds if (sec < 60) { return sec + ' sec. ago'; } let min = Math.floor(diff / 60000); // convert diff to minutes if (min < 60) { return min + ' min. ago'; } // format the date // add leading zeroes to single-digit day/month/hours/minutes let d = date; d = [ '0' + d.getDate(), '0' + (d.getMonth() + 1), '' + d.getFullYear(), '0' + d.getHours(), '0' + d.getMinutes() ].map(component => component.slice(-2)); // take last 2 digits of every component // join the components into date return d.slice(0, 3).join('.') + ' ' + d.slice(3).join(':'); } alert( formatDate(new Date(new Date - 1)) ); // "right now" alert( formatDate(new Date(new Date - 30 * 1000)) ); // "30 sec. ago" alert( formatDate(new Date(new Date - 5 * 60 * 1000)) ); // "5 min. ago" // yesterday's date like 31.12.2016 20:00 alert( formatDate(new Date(new Date - 86400 * 1000)) );

Alternative solution:

function formatDate(date) { let dayOfMonth = date.getDate(); let month = date.getMonth() + 1; let year = date.getFullYear(); let hour = date.getHours(); let minutes = date.getMinutes(); let diffMs = new Date() - date; let diffSec = Math.round(diffMs / 1000); let diffMin = diffSec / 60; let diffHour = diffMin / 60; // formatting year = year.toString().slice(-2); month = month < 10 ? '0' + month : month; dayOfMonth = dayOfMonth < 10 ? '0' + dayOfMonth : dayOfMonth; hour = hour < 10 ? '0' + hour : hour; minutes = minutes < 10 ? '0' + minutes : minutes; if (diffSec < 1) { return 'right now'; } else if (diffMin < 1) { return `${diffSec} sec. ago` } else if (diffHour < 1) { return `${diffMin} min. ago` } else { return `${dayOfMonth}.${month}.${year} ${hour}:${minutes}` } }

Open the solution with tests in a sandbox.