diff --git a/src/main/java/ru/ulstu/db/DbFileService.java b/src/main/java/ru/ulstu/db/DbFileService.java
index a55e9e7..f5ef631 100644
--- a/src/main/java/ru/ulstu/db/DbFileService.java
+++ b/src/main/java/ru/ulstu/db/DbFileService.java
@@ -15,8 +15,10 @@ import ru.ulstu.db.model.TimeSeriesSet;
 import ru.ulstu.service.UtilService;
 
 import java.io.BufferedReader;
+import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileReader;
+import java.io.FileWriter;
 import java.io.IOException;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -56,7 +58,7 @@ public class DbFileService implements DbService {
         String row;
         TimeSeries result = new TimeSeries(timeSeriesKey);
         while ((row = csvReader.readLine()) != null) {
-            TimeSeries partOfTimeSeries = new UtilService().getTimeSeriesFromString(row);
+            TimeSeries partOfTimeSeries = new UtilService().getTimeSeriesFromDateValueString(row);
             if (partOfTimeSeries.getLength() > 0) {
                 result.getValues().addAll(partOfTimeSeries.getValues());
             }
@@ -76,9 +78,11 @@ public class DbFileService implements DbService {
     }
 
     @Override
-    public boolean addTimeSeries(TimeSeriesSet timeSeriesSet, TimeSeries timeSeries) {
+    public boolean addTimeSeries(TimeSeriesSet timeSeriesSet, TimeSeries timeSeries) throws IOException {
         validateTimeSeriesSet(timeSeriesSet);
-
+        BufferedWriter writer = new BufferedWriter(new FileWriter(Paths.get(timeSeriesDbPath, timeSeriesSet.getKey()).toFile()));
+        writer.write(new UtilService().getTimeSeriesToDateValueString(timeSeries));
+        writer.close();
         return true;
     }
 
diff --git a/src/main/java/ru/ulstu/db/DbService.java b/src/main/java/ru/ulstu/db/DbService.java
index 4fc121c..b5b58de 100644
--- a/src/main/java/ru/ulstu/db/DbService.java
+++ b/src/main/java/ru/ulstu/db/DbService.java
@@ -22,5 +22,5 @@ public interface DbService {
 
     boolean addNewSet(String key);
 
-    boolean addTimeSeries(TimeSeriesSet timeSeriesSet, TimeSeries timeSeries);
+    boolean addTimeSeries(TimeSeriesSet timeSeriesSet, TimeSeries timeSeries) throws IOException;
 }
diff --git a/src/main/java/ru/ulstu/service/UtilService.java b/src/main/java/ru/ulstu/service/UtilService.java
index 7351583..44d44ec 100644
--- a/src/main/java/ru/ulstu/service/UtilService.java
+++ b/src/main/java/ru/ulstu/service/UtilService.java
@@ -59,4 +59,28 @@ public class UtilService {
                 .map(v -> v.getValue().toString().replace("\\.", ","))
                 .collect(Collectors.joining(";"));
     }
+
+    public String getTimeSeriesToDateValueString(TimeSeries timeSeries) {
+        return timeSeries
+                .getValues()
+                .stream()
+                .map(v -> v.getDate().toString() + ";" + v.getValue().toString().replace("\\.", ","))
+                .collect(Collectors.joining("\n"));
+    }
+
+    public TimeSeries getTimeSeriesFromDateValueString(String tsString) {
+        List<TimeSeriesValue> tsValues = Arrays.stream(tsString.split("\n"))
+                .filter(v -> {
+                    try {
+                        Double.parseDouble(v);
+                        return true;
+                    } catch (NumberFormatException e) {
+                        return false;
+                    }
+                })
+                .map(Double::parseDouble)
+                .map(TimeSeriesValue::new)
+                .collect(Collectors.toList());
+        return TimeSeriesUtils.fillDates(new TimeSeries(tsValues));
+    }
 }