diff --git a/draft-ietf-netmod-schedule-yang.md b/draft-ietf-netmod-schedule-yang.md
index 5ba48d7..7f13170 100644
--- a/draft-ietf-netmod-schedule-yang.md
+++ b/draft-ietf-netmod-schedule-yang.md
@@ -142,14 +142,17 @@ Also, this document uses the YANG terminology defined in {{Section 3 of !RFC7950
    time zone reference of the date and time values with local time format.
 
    The "validity" parameter specifies the date and time after which a schedule
-   will be considered as invalid.
+   will be considered as invalid. It determines the latest time that a schedule
+   can be executed by a system and takes precedence over similar attributes
+   that are provided at the schedule instance itself.
 
    The "max/min-allowed-start" parameters specify the maximum/minimum scheduled
    start date and time, a requested schedule will be rejected if the first
    occurrence of the schedule is later/earlier than the configured values.
 
    The "max-allowed-end" parameter specifies the maximum allowed end time of
-   the last occurrence.
+   the last occurrence. A requested schedule will be rejected if the end time
+   of last occurrence is later than the configured "max-allowed-end" value.
 
    The "discard-action" parameter specifies the action if a requested schedule
    is considered inactive or out-of-date.
diff --git a/yang/ietf-schedule.yang b/yang/ietf-schedule.yang
index 11dcaf6..4f5da05 100644
--- a/yang/ietf-schedule.yang
+++ b/yang/ietf-schedule.yang
@@ -273,27 +273,27 @@ module ietf-schedule {
       type yang:date-and-time;
       description
         "Specifies the maximum scheduled start date and time, a 
-         requested schedule instance whose first occurence after 
+         requested schedule instance whose first occurrence after 
          this value cannot be accepted by the entity. Specifically, 
          a requested schedule will be rejected if the first 
-         occurence of that new schedule exceeds
+         occurrence of that new schedule exceeds
          'max-allowed-start'.";
     }
     leaf min-allowed-start {
       type yang:date-and-time;
       description
         "Specifies the minimum scheduled start date and time, a 
-         requested schedule instance whose first occurence before 
+         requested schedule instance whose first occurrence before 
          this value cannot be accepted by the entity. Specifically, 
          a requested schedule will be rejected if the first  
-         occurence of that new schedule is scheduled before 
+         occurrence of that new schedule is scheduled before 
          'min-allowed-start'.";
     }
     leaf max-allowed-end {
       type yang:date-and-time;
       description
         "A requested schedule will be rejected if the end time of 
-         the last occurence exceed 'max-allowed-end'.";
+         the last occurrence exceeds 'max-allowed-end'.";
     }
     leaf discard-action {
       type identityref {
@@ -448,7 +448,7 @@ module ietf-schedule {
       }
       augment "recurrence-first" {
         description
-          "Add a parameter indicating how long the occurence 
+          "Adds a parameter indicating how long the occurrence 
            lasts.";
         leaf duration {
           type int32;
@@ -471,7 +471,7 @@ module ietf-schedule {
     uses recurrence {
       augment "recurrence-first" {
         description
-          "Add parameters indicating how long the occurrence 
+          "Adds parameters indicating how long the occurrence 
            lasts and time zone identifier of the occurrence.";
         leaf duration {
           type duration;