Format timestamps in markdown output for pdf/html consistently to inc…

…lude UTC

lib/galaxy/managers/markdown_util.py

@@ -504,6 +504,9 @@ class ToBasicMarkdownDirectiveHandler(GalaxyInternalMarkdownDirectiveHandler):
     def __init__(self, trans):
         self.trans = trans
 
+    def _format_printable_time(self, time):
+        return time.strftime("%Y-%m-%d, %H:%M:%S UTC")
+
     def handle_dataset_display(self, line, hda):
         name = hda.name or ""
         markdown = "---\n"
@@ -687,7 +690,7 @@ def handle_generate_galaxy_version(self, line, generate_version):
         return (content, True)
 
     def handle_generate_time(self, line, generate_time):
-        content = literal_via_fence(generate_time.isoformat())
+        content = literal_via_fence(self._format_printable_time(generate_time))
         return (content, True)
 
     def handle_instance_access_link(self, line, url):
@@ -720,7 +723,7 @@ def _handle_link(self, url, title=None):
         return (f"[{title}]({url})", True)
 
     def handle_invocation_time(self, line, invocation):
-        content = literal_via_fence(invocation.create_time.isoformat())
+        content = literal_via_fence(self._format_printable_time(invocation.create_time))
         return (content, True)
 
     def handle_dataset_name(self, line, hda):