From b4077713f5129f6924c65d8caf7f23bcb02c79eb Mon Sep 17 00:00:00 2001
From: Daniel Micay <danielmicay@gmail.com>
Date: Sun, 19 Mar 2023 02:02:47 -0400
Subject: [PATCH] improve network time documentation

---
 static/faq.html      | 25 ++++++++++++++-----------
 static/features.html |  4 ++++
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/static/faq.html b/static/faq.html
index 38de71fb..a3e6a0c4 100644
--- a/static/faq.html
+++ b/static/faq.html
@@ -806,17 +806,20 @@
                             repository.</p>
                         </li>
                         <li>
-                            <p>An HTTPS connection is made to https://time.grapheneos.org/generate_204 to
-                            update the time from the custom X-Time header field, which has millisecond
-                            precision, or falls back to the Date header if X-Time is not available with less
-                            precision. GrapheneOS also lowers the system clock drift warning from 2000 milliseconds
-                            to 250 milliseconds, and the time update threshold from 2000 milliseconds to 50
-                            milliseconds. This is a full and more precise replacement of Android's standard
-                            network time update implementation, which uses the cellular network when available
-                            with a fallback to SNTP when it's not available. Network time updates are security
-                            sensitive since certificate validation depends on having an accurate time, but
-                            the standard NTP / SNTP protocols used across most OSes have no authentication
-                            or encryption.</p>
+                            <p>An HTTPS connection is made to
+                            https://time.grapheneos.org/generate_204 to update the time with a
+                            millisecond precision X-Time header. As part of future support for
+                            using other services, it falls back to the standard Date header with
+                            second precision.</p>
+
+                            <p>This is a full replacement for Android's standard network time
+                            update implementation, which uses unauthentication SNTP (Simple
+                            Network Time Protocol) with fallback to the cellular network when it's
+                            not available (GNSS can also be used as a time source but is disabled
+                            by default, and OEMs can choose the priority order). Network time
+                            updates are security sensitive since certificate validation depends on
+                            having an accurate time, but the standard NTP / SNTP protocols used
+                            across most OSes have no authentication or encryption.</p>
 
                             <p>We plan to offer a toggle to use the standard functionality instead of
                             HTTPS-based time updates in order to blend in with other devices.</p>
diff --git a/static/features.html b/static/features.html
index 5e7a8dc0..86ddd833 100644
--- a/static/features.html
+++ b/static/features.html
@@ -953,6 +953,10 @@
                         <li>Screenshot shutter sound is toggleable using the "Touch sounds" option in Settings ➔
                         Sound &amp; vibration while still following the standard method of putting the device
                         on vibration/silent mode to turn off the screenshot shutter sound.</li>
+                        <li>More precise system clock via lowering the system clock time update
+                        threshold from 2000ms to 50ms and lowering the system clock drift warning
+                        from 2000ms to 250ms. This can be helpful for time-based protocols such as
+                        TOTP.</li>
                     </ul>
                 </section>
             </section>