Add convert date

content/extras/systime.md

@@ -2,15 +2,18 @@
 title: Systime
 ---
 
-You can use this form to convert to/from [systime](https://wiki.post-self.ink/wiki/Systime).
+You can use this form to convert to/from [systime](https://wiki.post-self.ink/wiki/Systime). This also includes dates in the Hebrew calendar, given their use in a few Post-Self projects.
 
 <div style="text-align: center;">
     <input type="text" id="systime" value="systime 1+21" /><br>
-    <input type="button" id="convert" value="Convert systime..." />
+    <input type="button" id="convertSystime" value="Convert systime..." />
+    <hr>
+    <input type="text" id="date" value="2125-01-21" /><br>
+    <input type="button" id="convertDate" value="Convert date..." />
 </div>
 <div id="output" />
 <script type="text/javascript">
-    document.getElementById('convert').addEventListener("click", (ev) => {
+    document.getElementById('convertSystime').addEventListener("click", (ev) => {
         fetch(`https://systime.post-self.ink/api/1/systime/${document.getElementById('systime').value}`)
             .then((response) => {
                 if (!response.ok) {
@@ -19,7 +22,20 @@ You can use this form to convert to/from [systime](https://wiki.post-self.ink/wi
                 }
                 return response.json();
             })
-            .then((json) => {
+            .then(display);
+    });
+    document.getElementById('convertDate').addEventListener("click", (ev) => {
+        fetch(`https://systime.post-self.ink/api/1/date/${document.getElementById('date').value}`)
+            .then((response) => {
+                if (!response.ok) {
+                    document.getElementById('output').innerHTML = `Error converting systime`;
+                    throw new Error(response.status);
+                }
+                return response.json();
+            })
+            .then(display);
+    });
+    function display(json) {
         document.getElementById('output').innerHTML = `
         <dl>
             <dt>Systime</dt>
@@ -29,7 +45,6 @@ You can use this form to convert to/from [systime](https://wiki.post-self.ink/wi
             <dt>Hebrew</dt>
             <dd>${json.hebrew.string}</dd>
         </dl>`;
-            });
+    }
-    });
 </script>