diff --git a/designs/bmc-health-monitor.md b/designs/bmc-health-monitor.md
index dd9d339..c8d8bd8 100644
--- a/designs/bmc-health-monitor.md
+++ b/designs/bmc-health-monitor.md
@@ -152,15 +152,15 @@
 "xyz.openbmc_project.HealthManager". The design proposes new
 [Metrics Dbus interfaces](https://gerrit.openbmc.org/c/openbmc/phosphor-dbus-interfaces/+/64914).
 
-| Interface Name                       | Purpose                                                                        |
-| :----------------------------------- | :----------------------------------------------------------------------------- |
-| xyz.openbmc_project.Metrics.Value    | Interface to represent value for Metrics.                                      |
-| xyz.openbmc_project.Metrics.Reset    | Interface to reset persistent Metrics counters.                                |
-| xyz.openbmc_project.Common.Threshold | Interface to represent Metric thresholds and signals for threshold violations. |
+| Interface Name                       | Purpose                                                                        | Required/Optional |
+| :----------------------------------- | :----------------------------------------------------------------------------- | :---------------- |
+| xyz.openbmc_project.Metrics.Value    | Interface to represent value for Metrics.                                      | Required          |
+| xyz.openbmc_project.Metrics.Reset    | Interface to reset persistent Metrics counters.                                | Optional          |
+| xyz.openbmc_project.Common.Threshold | Interface to represent Metric thresholds and signals for threshold violations. | Optional          |
+| xyz.openbmc_project.Time.EpochTime   | Interface to indicate when the metric was collected.                           | Optional          |
 
 Each metric will be exposed on a specific object path and above interfaces will
-be implemented at these paths. Reset Interfaces are optional and may only be
-implemented for persistent counters/intervals.
+be implemented at these paths.
 
 ```
 /xyz/openbmc_project