Javascript将当前时间转换为timeago

Question

I have been trying to convert the current time to timeago like facebook and twitter have (2 min ago, 30sec ago). For that, I am taking the current time and with the help of function converting it to approx time. The code is below:

 var current = new Date(); console.log(timeDifference(current, new Date(2018, 03, 27, 10, 30, 00, 00))); console.log(timeDifference(current, new Date(2018, 03, 27, 10, 00, 00, 00))); function timeDifference(current, previous) { var msPerMinute = 60 * 1000; var msPerHour = msPerMinute * 60; var msPerDay = msPerHour * 24; var msPerMonth = msPerDay * 30; var msPerYear = msPerDay * 365; var elapsed = current - previous; if (elapsed < msPerMinute) { return Math.round(elapsed / 1000) + ' seconds ago'; } else if (elapsed < msPerHour) { return Math.round(elapsed / msPerMinute) + ' minutes ago'; } else if (elapsed < msPerDay) { return Math.round(elapsed / msPerHour) + ' hours ago'; } else if (elapsed < msPerMonth) { return 'approximately ' + Math.round(elapsed / msPerDay) + ' days ago'; } else if (elapsed < msPerYear) { return 'approximately ' + Math.round(elapsed / msPerMonth) + ' months ago'; } else { return 'approximately ' + Math.round(elapsed / msPerYear) + ' years ago'; } } 

But, it is not working correctly and I can't seem to know why?

Answer 1

Your month is off by one (0 based). (May still return wrong result based on time zones of course.)

 var current = new Date(); console.log(timeDifference(current, new Date(2018, 02, 27, 10, 30, 00, 00))); console.log(timeDifference(current, new Date(2018, 02, 27, 10, 00, 00, 00))); function timeDifference(current, previous) { var msPerMinute = 60 * 1000; var msPerHour = msPerMinute * 60; var msPerDay = msPerHour * 24; var msPerMonth = msPerDay * 30; var msPerYear = msPerDay * 365; var elapsed = current - previous; if (elapsed < msPerMinute) { return Math.round(elapsed / 1000) + ' seconds ago'; } else if (elapsed < msPerHour) { return Math.round(elapsed / msPerMinute) + ' minutes ago'; } else if (elapsed < msPerDay) { return Math.round(elapsed / msPerHour) + ' hours ago'; } else if (elapsed < msPerMonth) { return 'approximately ' + Math.round(elapsed / msPerDay) + ' days ago'; } else if (elapsed < msPerYear) { return 'approximately ' + Math.round(elapsed / msPerMonth) + ' months ago'; } else { return 'approximately ' + Math.round(elapsed / msPerYear) + ' years ago'; } } 

Answer 2

The problem is in your tests as month starts with 0. Change

console.log(timeDifference(current, new Date(2018, 03, 27, 10, 30, 00, 00)));
console.log(timeDifference(current, new Date(2018, 03, 27, 10, 00, 00, 00)));

to

console.log(timeDifference(current, new Date(2018, 02, 27, 10, 30, 00, 00)));
console.log(timeDifference(current, new Date(2018, 02, 27, 10, 00, 00, 00)));

and your code works fine.