diff --git a/library/src/calculator_functions.cpp b/library/src/calculator_functions.cpp
index c717675..60f18ae 100644
--- a/library/src/calculator_functions.cpp
+++ b/library/src/calculator_functions.cpp
@@ -196,17 +196,48 @@ std::optional<ATBTariffCarryOver> getCarryOver(Configuration const *cfg, QDateTi
 
     ATBTime inputTime(dt.time());
     auto const &carryOverRange = cfg->TariffCarryOvers.equal_range(weekDay);
+
+    QDate d; // check if a special date is configured in tariff-file for this day
     for (auto i = carryOverRange.first; i != carryOverRange.second; ++i) {
         ATBTariffCarryOver const &carryOver = i->second;
-        TimeRange const &carryOverTimeRange = carryOver.m_range;
-        if (inputTime >= carryOverTimeRange.m_start && inputTime < carryOverTimeRange.m_end) {
-            // qCritical() << __func__ << ":" << __LINE__ << carryOverTimeRange.m_start.toString(Qt::ISODate);
-            // qCritical() << __func__ << ":" << __LINE__ << carryOverTimeRange.m_end.toString(Qt::ISODate);
-            value = value.value_or(carryOver);
+        if (!carryOver.m_date.isNull() && carryOver.m_date.isValid() && carryOver.m_date == dt.date()) {
+            d = dt.date();
+            // qCritical() << __func__ << ":" << __LINE__ << "found special day" << d.toString(Qt::ISODate);
             break;
         }
     }
 
+    if (!d.isNull() && d.isValid()) {
+        for (auto i = carryOverRange.first; i != carryOverRange.second; ++i) {
+            ATBTariffCarryOver const &carryOver = i->second;
+
+            if (!carryOver.m_date.isNull() && carryOver.m_date.isValid() && carryOver.m_date == d) {
+                TimeRange const &carryOverTimeRange = carryOver.m_range;
+                if (inputTime >= carryOverTimeRange.m_start && inputTime < carryOverTimeRange.m_end) {
+                    // qCritical() << __func__ << ":" << __LINE__ << carryOverTimeRange.m_start.toString(Qt::ISODate);
+                    // qCritical() << __func__ << ":" << __LINE__ << carryOverTimeRange.m_end.toString(Qt::ISODate);
+                    value = value.value_or(carryOver);
+                    break;
+                }
+            }
+        }
+    } else {
+        // qCritical() << __func__ << ":" << __LINE__ << "no special day" << dt.date().toString(Qt::ISODate);
+        for (auto i = carryOverRange.first; i != carryOverRange.second; ++i) {
+            ATBTariffCarryOver const &carryOver = i->second;
+            if (carryOver.m_date.isNull() || !carryOver.m_date.isValid()) {
+                // qCritical() << __func__ << ":" << __LINE__ << "default";
+                TimeRange const &carryOverTimeRange = carryOver.m_range;
+                if (inputTime >= carryOverTimeRange.m_start && inputTime < carryOverTimeRange.m_end) {
+                    // qCritical() << __func__ << ":" << __LINE__ << carryOverTimeRange.m_start.toString(Qt::ISODate);
+                    // qCritical() << __func__ << ":" << __LINE__ << carryOverTimeRange.m_end.toString(Qt::ISODate);
+                    value = value.value_or(carryOver);
+                    break;
+                }
+            }
+        }
+    }
+
     return value;
 }