Propose tezDate type. Minimal tests

package.json

@@ -7,7 +7,8 @@
   "scripts": {
     "test": "jest",
     "build": "rm -rf ./build && npx tsc --outDir build",
-    "postpublish": "PACKAGE_VERSION=$(cat package.json | grep \\\"version\\\" | head -1 | awk -F: '{ print $2 }' | sed 's/[\",]//g' | tr -d '[[:space:]]') && git tag v$PACKAGE_VERSION && git push --tags"
+    "postpublish": "PACKAGE_VERSION=$(cat package.json | grep \\\"version\\\" | head -1 | awk -F: '{ print $2 }' | sed 's/[\",]//g' | tr -d '[[:space:]]') && git tag v$PACKAGE_VERSION && git push --tags",
+    "watch-test": "jest --watch" 
   },
   "repository": {
     "type": "git",

src/main.ts

@@ -443,6 +443,30 @@ export class Duration implements ArchetypeType {
   }
 }
 
+
+export class TezDate implements ArchetypeType {
+  private _content: Date
+  constructor(v: Date = new Date()) {
+    this._content = new Date(v.getTime() - v.getMilliseconds())
+  }
+  equals(x: TezDate): boolean {
+    return this.toSecond() === x.toSecond()
+  }
+  toSecond(): number {
+    return this._content.getTime() / 1000
+  }
+  addDuration(dur: Duration): TezDate {
+    return new TezDate(
+      new Date(this.toSecond()*1000 + dur.toSecond()*1000) 
+  )}
+  addDurationLiteral(x : string) : TezDate {
+    return this.addDuration(new Duration(x))
+  }
+  toDate(): Date { 
+    return new Date(this._content)
+  }
+}
+
 export class Entrypoint implements ArchetypeType {
   addr: string
   name: string

test/main.spec.ts

@@ -1,6 +1,6 @@
+import {cmp_date } from './../src/main';
 import BigNumber from 'bignumber.js';
-import { Address, Chain_id, Duration, Key, Micheline, mich_to_ticket, Mstring, Nat, Rational, Signature, Ticket, Key_hash } from '../src/main'
-
+import { Address, Chain_id, TezDate, Duration, Key, Micheline, mich_to_ticket, Mstring, Nat, Rational, Signature, Ticket, Key_hash } from '../src/main'
 describe('ArchetypeType', () => {
 
   describe('Address', () => {
@@ -150,6 +150,37 @@ describe('Chain_id', () => {
 
   })
 
+  describe('tezDate', () => {
+
+    test('Convert Date to TezDate and back again succesfully ', () => {
+      const native_date_now = new Date()
+      const tez_date_now = new TezDate(native_date_now)
+      const native_date_now_two = tez_date_now.toDate()
+      expect(cmp_date(native_date_now, native_date_now_two)).toEqual(true)
+    });
+
+      test('Sucessfully add durations to a TezDate', () => {
+      const MINUTES = 2
+      const native_date_now = new Date()
+      const native_date_soon = new Date(native_date_now.getTime() + MINUTES*60000)
+      const tez_date_now = new TezDate(native_date_now)
+      const tez_date_soon = tez_date_now.addDuration(new Duration(`${MINUTES}m`))
+      expect(cmp_date(tez_date_soon.toDate(), native_date_soon)).toEqual(true)
+
+    });
+
+    test('Sucessfully add duration string to a TezDate', () => {
+      const MINUTES = 2
+      const native_date_now = new Date()
+      const native_date_soon = new Date(native_date_now.getTime() + MINUTES*60000)
+      const tez_date_now = new TezDate(native_date_now)
+      const tez_date_soon = tez_date_now.addDurationLiteral(`${MINUTES}m`)
+      expect(cmp_date(tez_date_soon.toDate(), native_date_soon)).toEqual(true)
+    }); 
+  })
+
+
+
   describe('Key', () => {
     test('Fails with empty string', () => {
       const input = ""