2 files changed, 90 insertions, 1 deletions
diff --git a/cisa/date.go b/cisa/date.go
index b36b73c..b3b6528 100644
--- a/cisa/date.go
+++ b/cisa/date.go
@@ -1,6 +1,7 @@
 package cisa
 
 import (
+  "encoding/json"
   "fmt"
   "regexp"
   "strconv"
@@ -135,5 +136,29 @@ func (me Date) String() string {
   y, m, d := me.GetComponents()
 
   // return string
-  return fmt.Sprintf("%d-%d-%d", y, m, d)
+  return fmt.Sprintf("%04d-%02d-%02d", y, m, d)
+}
+
+// Unmarshal date from JSON string.
+func (me *Date) UnmarshalJSON(b []byte) error {
+  // decode json string
+  var s string
+  if err := json.Unmarshal(b, &s); err != nil {
+    return err
+  }
+
+  // create date
+  d, err := NewDate([]byte(s))
+  if err != nil {
+    return err
+  }
+
+  // save result, return success
+  *me = d
+  return nil
+}
+
+// Marshal Date as JSON string.
+func (d Date) MarshalJSON() ([]byte, error) {
+  return json.Marshal(d.String())
 }
diff --git a/cisa/date_test.go b/cisa/date_test.go
index c64f618..47e152e 100644
--- a/cisa/date_test.go
+++ b/cisa/date_test.go
@@ -1,6 +1,7 @@
 package cisa
 
 import (
+  "encoding/json"
   "fmt"
   "reflect"
   "testing"
@@ -308,3 +309,66 @@ func TestString(t *testing.T) {
     })
   }
 }
+
+func TestDateUnmarshalJSON(t *testing.T) {
+  passTests := []struct {
+    val string
+    exp string
+  } {
+    { `"2022-02-03"`, "2022-02-03" },
+  }
+
+  for _, test := range(passTests) {
+    var got Date
+    if err := json.Unmarshal([]byte(test.val), &got); err != nil {
+      t.Error(err)
+    } else if got.String() != test.exp {
+      t.Errorf("got \"%s\", exp \"%s\"", got.String(), test.exp)
+    }
+  }
+
+  failTests := []struct {
+    name string
+    val  string
+  } {
+    { "fail-str", "asdf" },
+    { "fail-parse", "\"asdf\"" },
+  }
+
+  for _, test := range(failTests) {
+    t.Run(test.name, func(t *testing.T) {
+      var got Date
+      if err := got.UnmarshalJSON([]byte(test.val)); err == nil {
+        t.Errorf("got \"%v\" exp error", got)
+      }
+    })
+  }
+
+}
+
+func TestDateMarshalJSON(t *testing.T) {
+  tests := []struct {
+    val string
+    exp string
+  } {
+    { "2022-10-31", `"2022-10-31"` },
+  }
+
+  for _, test := range(tests) {
+    t.Run(test.val, func(t *testing.T) {
+      // create date
+      dt, err := NewDate([]byte(test.val))
+      if err != nil {
+        t.Error(err)
+        return
+      }
+
+      // get/check string
+      if got, err := dt.MarshalJSON(); err != nil {
+        t.Error(err)
+      } else if string(got) != test.exp {
+        t.Errorf("got \"%s\", exp \"%s\"", got, test.exp)
+      }
+    })
+  }
+}