Function substract

substract(date, amount, timeUnit): Date
JMap.Util.Date.substract

Returns a date, that is the given date minus the given amount of unit.

It's safe, the given date is not changed.

Possible time units are : "seconds" | "minutes" | "hours" | "days" | "weeks" | "months" |"years"
Parameters
- date: JDateLike
  the date from
- amount: number
  amount of unit
- timeUnit: JTIME_UNITS
  time unit
Returns Date
Throws
Example
```
// returns the date 2 days in the past
JMap.Util.Date.substract(new Date(), 2, "days")

// returns the date 2 seconds in the past
JMap.Util.Date.substract(new Date(), 2, "seconds")
```