Parse ticks to datetime

Question

How can I convert a tick, such as 1298011537289 to a DateTime in Ruby?

The value I need to convert is coming from a JavaScript Date.now() call, so it's in milliseconds

Answer 1

Per the Ruby docs:

myTime = Time.at(1298011537289)

or since you're using milliseconds rather than seconds:

myTime = Time.at(1298011537289 / 1000)

But that will only remove sub-second precision, to retain it:

myTime = Time.at(Rational(1298011537289, 1000))

Answer 2

Use strptime and parse it with the format %Q - Number of microseconds since 1970-01-01 00:00:00 UTC.

Example: DateTime.strptime "1352748750274", "%Q"

Answer 3

Assuming the value is in milliseconds, this is how I'd do it:

require 'date'
DateTime.parse(Time.at(1298011537289 / 1000).to_s) # => #<DateTime: 2011-02-17T23:45:37-07:00 (212164771537/86400,-7/24,2299161)>