Intro

Simply periods that are commonly used in javascript:

• 100% constants - no API to learn
• Singular grammer (DAY not DAYS)
• Shorthand versions when commonly exists

const MS = 1
const SECOND =      SEC =   1000 * MS
const MINUTE =      MIN =   60 * SEC
const HOUR =        HR =    60 * MIN
const DAY =                 24 * HOUR
const WEEK =        WK =    7 * DAY
const YEAR =        YR =    365 * HOUR
const DECADE =      DEC =   10 * YEAR
const CENTUARY =    CEN =   100 * YEAR
const MILLENIUM =           100 * YEAR