diff --git a/src/libcalamares/locale/TimeZone.cpp b/src/libcalamares/locale/TimeZone.cpp
index 6eabef6e8..4c641cd17 100644
--- a/src/libcalamares/locale/TimeZone.cpp
+++ b/src/libcalamares/locale/TimeZone.cpp
@@ -337,14 +337,14 @@ ZonesModel::find( const QString& region, const QString& zone ) const
 }
 
 STATICTEST const TimeZoneData*
-find( const ZoneVector& zones, std::function< double( const TimeZoneData* ) > distance )
+find( const ZoneVector& zones, const std::function< double( const TimeZoneData* ) >& distanceFunc )
 {
     double smallestDistance = 1000000.0;
     const TimeZoneData* closest = nullptr;
 
     for ( const auto* zone : zones )
     {
-        double thisDistance = distance( zone );
+        double thisDistance = distanceFunc( zone );
         if ( thisDistance < smallestDistance )
         {
             closest = zone;
@@ -354,6 +354,12 @@ find( const ZoneVector& zones, std::function< double( const TimeZoneData* ) > di
     return closest;
 }
 
+const TimeZoneData*
+ZonesModel::find( const std::function< double( const TimeZoneData* ) >& distanceFunc ) const
+{
+    return CalamaresUtils::Locale::find( m_private->m_zones, distanceFunc );
+}
+
 const TimeZoneData*
 ZonesModel::find( double latitude, double longitude ) const
 {
@@ -384,7 +390,7 @@ ZonesModel::find( double latitude, double longitude ) const
         return latitudeDifference + longitudeDifference;
     };
 
-    return CalamaresUtils::Locale::find( m_private->m_zones, distance );
+    return find( distance );
 }
 
 QObject*
diff --git a/src/libcalamares/locale/TimeZone.h b/src/libcalamares/locale/TimeZone.h
index 1d4b4a8ff..cc0c35ea2 100644
--- a/src/libcalamares/locale/TimeZone.h
+++ b/src/libcalamares/locale/TimeZone.h
@@ -167,6 +167,17 @@ public:
 
     Iterator begin() const { return Iterator( m_private ); }
 
+    /** @brief Look up TZ data based on an arbitrary distance function
+     *
+     * This is a generic method that can define distance in whatever
+     * coordinate system is wanted; returns the zone with the smallest
+     * distance. The @p distanceFunc must return "the distance" for
+     * each zone. It would be polite to return something non-negative.
+     *
+     * Note: not a slot, because the parameter isn't moc-able.
+     */
+    const TimeZoneData* find( const std::function< double( const TimeZoneData* ) >& distanceFunc ) const;
+
 public Q_SLOTS:
     /** @brief Look up TZ data based on its name.
      *
@@ -176,7 +187,10 @@ public Q_SLOTS:
 
     /** @brief Look up TZ data based on the location.
      *
-     * Returns the nearest zone to the given lat and lon.
+     * Returns the nearest zone to the given lat and lon. This is a
+     * convenience function for calling find(), below, with a standard
+     * distance function based on the distance between the given
+     * location (lat and lon) and each zone's given location.
      */
     const TimeZoneData* find( double latitude, double longitude ) const;