diff --git a/packages/core/hap.mjs b/packages/core/hap.mjs
index 44ff7ba0..b74649c6 100644
--- a/packages/core/hap.mjs
+++ b/packages/core/hap.mjs
@@ -1,4 +1,3 @@
-
 export class Hap {
   /*
       Event class, representing a value active during the timespan
@@ -77,6 +76,10 @@ export class Hap {
     );
   }
 
+  showWhole() {
+    return `${this.whole == undefined ? '~' : this.whole.show()}: ${this.value}`;
+  }
+
   combineContext(b) {
     const a = this;
     return { ...a.context, ...b.context, locations: (a.context.locations || []).concat(b.context.locations || []) };
diff --git a/packages/core/timespan.mjs b/packages/core/timespan.mjs
index 5c398da1..a55e1de8 100644
--- a/packages/core/timespan.mjs
+++ b/packages/core/timespan.mjs
@@ -28,6 +28,10 @@ export class TimeSpan {
     return spans;
   }
 
+  get duration() {
+    return this.end.sub(this.begin);
+  }
+
   cycleArc() {
     // Shifts a timespan to one of equal duration that starts within cycle zero.
     // (Note that the output timespan probably does not start *at* Time 0 --