votedecay.js

 calculateVoteWeight () {
   let decayWeeks = 13
   let timestamp_epoch = 946684800000
   let dates = (Date.now() / 1000) - (timestamp_epoch / 1000)
   let weight = Math.floor(dates / (86400 * 7)) / decayWeeks
   return Math.pow(2, weight)
 }

async calculateVoteDecayPercentage (staked, last_vote_weight) {
   let stake = staked / Math.pow(10, 8)
   const lastVoteWeight = (last_vote_weight / calculateVoteWeight()) / Math.pow(10, 8)
   return (lastVoteWeight / stake).toFixed(2)
}