npm i pretty-time-decimal
Decimal to pretty string:
const { decimalToTimeStr } = require('pretty-time-decimal');
decimalToTimeStr(3.5) // '3:30'
decimalToTimeStr(3.75) // '3:45'
decimalToTimeStr(3 + (5 / 60)) // '3:05'
String to decimal:
const { timeStrToDecimal } = require('pretty-time-decimal');
timeStrToDecimal('3:30') // 3.5
timeStrToDecimal('3:45') // 3.75
timeStrToDecimal('3:05') // 3 + (5 / 60)