diff --git a/src/connections/spec/common.md b/src/connections/spec/common.md
index f071da2827..a6ca65ab4f 100644
--- a/src/connections/spec/common.md
+++ b/src/connections/spec/common.md
@@ -304,6 +304,9 @@ Every API call has four timestamps, `originalTimestamp`, `timestamp`, `sentAt` a
 
 **All timestamps are [ISO-8601](http://en.wikipedia.org/wiki/ISO_8601) date strings.**
 
+> note ""
+> **NOTE:** ISO-8601 date strings with timezones included are required when using timestamps with [Personas](/docs/personas/). Sending custom traits without a timezone included in the timestamp will result in the value not being saved.
+
 ### Timestamp Overview
 
 <table>
@@ -343,7 +346,7 @@ Every API call has four timestamps, `originalTimestamp`, `timestamp`, `sentAt` a
   </tr>
   <tr>
     <td>`receivedAt`</td>
-    <td>time on Segment server clock when call was received</td>
+    <td>Time on Segment server clock when call was received</td>
     <td>
       Used by Segment to calculate `timestamp`, and used as sort key in Warehouses.
       <br><br>
diff --git a/src/connections/storage/warehouses/schema.md b/src/connections/storage/warehouses/schema.md
index 288968c3d0..4e2cd0e3a4 100644
--- a/src/connections/storage/warehouses/schema.md
+++ b/src/connections/storage/warehouses/schema.md
@@ -336,6 +336,9 @@ All four timestamps pass through to your Warehouse for every ETL'd event. In mos
 
 `received_at` does not ensure chronology of events.  For queries based on event chronology, `timestamp` should be used.
 
+> note ""
+> **NOTE:** ISO-8601 date strings with timezones included are required when using timestamps with [Personas](/docs/personas/). Sending custom traits without a timezone included in the timestamp will result in the value not being saved. 
+
 To learn more about timestamps in Segment, [read our timestamps overview](/docs/connections/spec/common/#timestamps) in the Segment Spec.
 
 ## id