Date checks return datetime verbatim & use seconds in test data.

lib/index.js

@@ -613,14 +613,13 @@ export function _checkCredential({
     }
     // check if `now` is before `issuanceDate` on verification
     if(mode === 'verify') {
-      let {issuanceDate} = credential;
       assertDateString({credential, prop: 'issuanceDate'});
       // check if `now` is before `issuanceDate`
-      issuanceDate = new Date(issuanceDate);
+      const issuanceDate = new Date(credential.issuanceDate);
       if(now < issuanceDate) {
         throw new Error(
           `The current date time (${now.toISOString()}) is before the ` +
-          `"issuanceDate" (${issuanceDate.toISOString()}).`);
+          `"issuanceDate" (${credential.issuanceDate}).`);
       }
     }
   }
@@ -634,7 +633,7 @@ export function _checkCredential({
         if(now > validUntil) {
           throw new Error(
             `The current date time (${now.toISOString()}) is after ` +
-            `"validUntil" (${validUntil.toISOString()}).`);
+            `"validUntil" (${credential.validUntil}).`);
         }
       }
       if(validFrom) {
@@ -644,7 +643,7 @@ export function _checkCredential({
         if(now < validFrom) {
           throw new Error(
             `The current date time (${now.toISOString()}) is before ` +
-            `"validFrom" (${validFrom.toISOString()}).`);
+            `"validFrom" (${credential.validFrom}).`);
         }
       }
     }

test/10-verify.spec.js

@@ -784,7 +784,7 @@ for(const [version, mockCredential] of versionedCredentials) {
           const credential = jsonld.clone(mockCredential);
           credential.issuer = 'did:example:12345';
           credential.issuanceDate = createSkewedTimeStamp({skewYear: 1});
-          const now = createSkewedTimeStamp({skewYear: 0});
+          const now = new Date();
           let error;
           try {
             vc._checkCredential({credential, now});
@@ -794,7 +794,7 @@ for(const [version, mockCredential] of versionedCredentials) {
           should.exist(error,
             'Should throw error when "now" is before "issuanceDate"');
           error.message.should.contain(
-            `The current date time (${now}) is before the ` +
+            `The current date time (${now.toISOString()}) is before the ` +
             `"issuanceDate" (${credential.issuanceDate}).`);
         });
       }

test/helpers.js

@@ -9,5 +9,6 @@
  */
 export function createSkewedTimeStamp({date = new Date(), skewYear}) {
   date.setFullYear(date.getFullYear() + skewYear);
-  return date.toISOString();
+  const isoString = date.toISOString();
+  return isoString.substr(0, isoString.length - 5) + 'Z';
 }