audiobookshelf/server/libs/jsonwebtoken/lib/timespan.js

const ms = require('ms')

module.exports = function (time, iat) {
  var timestamp = iat || Math.floor(Date.now() / 1000)

  if (typeof time === 'string') {
    var milliseconds = ms(time)
    if (typeof milliseconds === 'undefined') {
      return
    }
    return Math.floor(timestamp + milliseconds / 1000)
  } else if (typeof time === 'number') {
    return timestamp + time
  } else {
    return
  }
}