diff --git a/timespans/activationperiod.go b/timespans/activationperiod.go
new file mode 100644
index 000000000..bf9ed47ce
--- /dev/null
+++ b/timespans/activationperiod.go
@@ -0,0 +1,77 @@
+package	timespans
+
+import (
+	"time"
+	"strings"
+	"strconv"
+)
+
+const LAYOUT = "2006-01-02T15:04:05Z07:00"
+
+/*
+The struture that is saved to storage.
+*/
+type ActivationPeriod struct {
+	ActivationTime time.Time
+	Intervals      []*Interval
+}
+
+/*
+Adds one ore more intervals to the internal interval list.
+*/
+func (ap *ActivationPeriod) AddInterval(is ...*Interval) {
+	for _, i := range is {
+		ap.Intervals = append(ap.Intervals, i)
+	}
+}
+
+/*
+Serializes the objects for the storage.
+*/
+func (ap *ActivationPeriod) store() (result string){	
+	result += ap.ActivationTime.Format(LAYOUT) + ";"
+	var is string
+	for _,i := range ap.Intervals {
+		is = strconv.Itoa(int(i.Month)) + "|"
+		is += strconv.Itoa(i.MonthDay) + "|"
+		for _, wd := range i.WeekDays {
+			is += strconv.Itoa(int(wd)) + ","
+		}
+		is = strings.TrimRight(is, ",")  + "|"
+		is += i.StartTime + "|"
+		is += i.EndTime + "|"
+		is += strconv.FormatFloat(i.Ponder, 'f', -1, 64) + "|"
+		is += strconv.FormatFloat(i.ConnectFee, 'f', -1, 64) + "|"
+		is += strconv.FormatFloat(i.Price, 'f', -1, 64) + "|"
+		is += strconv.FormatFloat(i.BillingUnit, 'f', -1, 64)
+		result += is + ";"
+	}	
+	return 
+}
+
+/*
+De-serializes the objects for the storage.
+*/
+func (ap *ActivationPeriod) restore(input string) {			
+	elements := strings.Split(input, ";")	
+	ap.ActivationTime, _ = time.Parse(LAYOUT, elements[0])
+	for _, is := range elements[1:len(elements) - 1]{		
+		i := &Interval{}
+		ise := strings.Split(is, "|")		
+		month, _ := strconv.Atoi(ise[0])
+		i.Month = time.Month(month)
+		i.MonthDay, _ = strconv.Atoi(ise[1])		 
+		for _,d := range strings.Split(ise[2], ","){
+			wd,_ :=  strconv.Atoi(d)
+			i.WeekDays = append(i.WeekDays, time.Weekday(wd))
+		}
+		i.StartTime = ise[3]
+		i.EndTime = ise[4]		
+		i.Ponder, _ = strconv.ParseFloat(ise[5], 64)		 
+		i.ConnectFee, _ = strconv.ParseFloat(ise[6], 64)
+		i.Price, _ = strconv.ParseFloat(ise[7], 64)
+		i.BillingUnit, _ = strconv.ParseFloat(ise[8], 64)
+		
+		ap.Intervals = append(ap.Intervals, i)
+	}	
+}
diff --git a/timespans/activationperiod_test.go b/timespans/activationperiod_test.go
new file mode 100644
index 000000000..acfd96699
--- /dev/null
+++ b/timespans/activationperiod_test.go
@@ -0,0 +1,65 @@
+package timespans
+
+import (
+	"testing"
+	"time"
+	//"log"
+)
+
+func TestApStoreRestore(t *testing.T) {	
+	d := time.Date(2012, time.February, 1, 14, 30, 1, 0, time.UTC)
+	i := &Interval{Month: time.February,
+		MonthDay:  1,
+		WeekDays:  []time.Weekday{time.Wednesday, time.Thursday},
+		StartTime: "14:30:00",
+		EndTime:   "15:00:00"}	
+	ap := ActivationPeriod{ActivationTime: d}
+	ap.AddInterval(i)
+	result := ap.store()
+	expected := "2012-02-01T14:30:01Z;2|1|3,4|14:30:00|15:00:00|0|0|0|0;"
+	if result != expected {
+		t.Errorf("Expected %q was %q", expected, result)
+	}
+	ap1 := ActivationPeriod{}
+	ap1.restore(result)
+	if ap1.ActivationTime != ap.ActivationTime {
+		t.Errorf("Expected %v was %v", ap.ActivationTime, ap1.ActivationTime)
+	}
+	i1 := ap1.Intervals[0]
+	if i1.Month != i.Month {
+		t.Errorf("Expected %q was %q", i.Month, i1.Month)	
+	}
+	if i1.MonthDay != i.MonthDay {
+		t.Errorf("Expected %q was %q", i.MonthDay, i1.MonthDay)	
+	}
+	for j,wd := range i1.WeekDays {
+		if wd != i1.WeekDays[j] {
+			t.Errorf("Expected %q was %q", i.StartTime, i1.StartTime)	
+		}	
+	}
+	if i1.StartTime != i.StartTime {
+		t.Errorf("Expected %q was %q", i.StartTime, i1.StartTime)	
+	}
+	if i1.EndTime != i.EndTime {
+		t.Errorf("Expected %q was %q", i.EndTime, i1.EndTime)	
+	}
+	if i1.Ponder != i.Ponder {
+		t.Errorf("Expected %q was %q", i.Ponder, i1.Ponder)	
+	}
+	if i1.ConnectFee != i.ConnectFee {
+		t.Errorf("Expected %q was %q", i.ConnectFee, i1.ConnectFee)	
+	}
+	if i1.Price != i.Price {
+		t.Errorf("Expected %q was %q", i.Price, i1.Price)	
+	}
+	if i1.BillingUnit != i.BillingUnit {
+		t.Errorf("Expected %q was %q", i.BillingUnit, i1.BillingUnit)	
+	}
+}
+
+func BenchmarkRestore(b *testing.B) {	
+	ap1 := ActivationPeriod{}
+	for i := 0; i < b.N; i++ {
+		ap1.restore("1328106601;2|1|3,4|14:30:00|15:00:00|0|0|0|0;")
+	}
+}
diff --git a/timespans/calldesc.go b/timespans/calldesc.go
index d19c2fae5..d180650e7 100644
--- a/timespans/calldesc.go
+++ b/timespans/calldesc.go
@@ -4,70 +4,8 @@ import (
 	"fmt"
 	"time"
 	"strings"
-	"strconv"
 )
 
-const LAYOUT = "2006-01-02T15:04:05Z07:00"
-
-/*
-The struture that is saved to storage.
-*/
-type ActivationPeriod struct {
-	ActivationTime time.Time
-	Intervals      []*Interval
-}
-
-func (ap *ActivationPeriod) AddInterval(is ...*Interval) {
-	for _, i := range is {
-		ap.Intervals = append(ap.Intervals, i)
-	}
-}
-
-func (ap *ActivationPeriod) store() (result string){	
-	result += ap.ActivationTime.Format(LAYOUT) + ";"
-	var is string
-	for _,i := range ap.Intervals {
-		is = strconv.Itoa(int(i.Month)) + "|"
-		is += strconv.Itoa(i.MonthDay) + "|"
-		for _, wd := range i.WeekDays {
-			is += strconv.Itoa(int(wd)) + ","
-		}
-		is = strings.TrimRight(is, ",")  + "|"
-		is += i.StartTime + "|"
-		is += i.EndTime + "|"
-		is += strconv.FormatFloat(i.Ponder, 'f', -1, 64) + "|"
-		is += strconv.FormatFloat(i.ConnectFee, 'f', -1, 64) + "|"
-		is += strconv.FormatFloat(i.Price, 'f', -1, 64) + "|"
-		is += strconv.FormatFloat(i.BillingUnit, 'f', -1, 64)
-		result += is + ";"
-	}	
-	return 
-}
-
-func (ap *ActivationPeriod) restore(input string) {			
-	elements := strings.Split(input, ";")	
-	ap.ActivationTime, _ = time.Parse(LAYOUT, elements[0])
-	for _, is := range elements[1:len(elements) - 1]{		
-		i := &Interval{}
-		ise := strings.Split(is, "|")		
-		month, _ := strconv.Atoi(ise[0])
-		i.Month = time.Month(month)
-		i.MonthDay, _ = strconv.Atoi(ise[1])		 
-		for _,d := range strings.Split(ise[2], ","){
-			wd,_ :=  strconv.Atoi(d)
-			i.WeekDays = append(i.WeekDays, time.Weekday(wd))
-		}
-		i.StartTime = ise[3]
-		i.EndTime = ise[4]		
-		i.Ponder, _ = strconv.ParseFloat(ise[5], 64)		 
-		i.ConnectFee, _ = strconv.ParseFloat(ise[6], 64)
-		i.Price, _ = strconv.ParseFloat(ise[7], 64)
-		i.BillingUnit, _ = strconv.ParseFloat(ise[8], 64)
-		
-		ap.Intervals = append(ap.Intervals, i)
-	}	
-}
-
 /*
 The input stucture that contains call information.
 */
@@ -78,12 +16,19 @@ type CallDescriptor struct {
 	ActivationPeriods                  []*ActivationPeriod
 }
 
+/*
+Adds an activation period that applyes to current call descriptor.
+*/
 func (cd *CallDescriptor) AddActivationPeriod(aps ...*ActivationPeriod) {
 	for _, ap := range aps {
 		cd.ActivationPeriods = append(cd.ActivationPeriods, ap)
 	}
 }
 
+/*
+Creates a string ready for storage containing the serialization of all
+activation periods held in the internal list.
+*/
 func (cd *CallDescriptor) EncodeValues() (result string) {
 	for _, ap := range cd.ActivationPeriods {
 		result += ap.store() + "\n"
@@ -91,6 +36,9 @@ func (cd *CallDescriptor) EncodeValues() (result string) {
 	return 
 }
 
+/*
+Restores the activation periods list from a storage string.
+*/
 func (cd *CallDescriptor) decodeValues(v string) {
 	for _, aps := range strings.Split(v, "\n") {
 		if(len(aps)>0){
@@ -101,10 +49,16 @@ func (cd *CallDescriptor) decodeValues(v string) {
 	}
 }
 
+/*
+Constructs the key for the storage lookup.
+*/
 func (cd *CallDescriptor) GetKey() string {
 	return fmt.Sprintf("%s:%s:%s", cd.CstmId, cd.Subject, cd.DestinationPrefix)
 }
 
+/*
+Finds the intervals applicable to the call descriptior.
+*/
 func (cd *CallDescriptor) getActiveIntervals() (is []*Interval) {
 	now := time.Now()
 	// add a second in the future to be able to pick the active timestamp
@@ -122,6 +76,9 @@ func (cd *CallDescriptor) getActiveIntervals() (is []*Interval) {
 	return
 }
 
+/*
+Splits the call timespan into sub time spans accordin to the received intervals.
+*/
 func (cd *CallDescriptor) splitInTimeSpans(intervals []*Interval) (timespans []*TimeSpan) {
 	ts1 := &TimeSpan{TimeStart: cd.TimeStart, TimeEnd: cd.TimeEnd}
 	timespans = append(timespans, ts1)
@@ -138,6 +95,7 @@ func (cd *CallDescriptor) splitInTimeSpans(intervals []*Interval) (timespans []*
 }
 
 /*
+Creates a CallCost structure with the cost nformation calculated for the received CallDescriptor.
  */
 func (cd *CallDescriptor) GetCost(sg StorageGetter) (result *CallCost, err error) {
 
@@ -170,4 +128,4 @@ type CallCost struct {
 	CstmId, Subject, DestinationPrefix string
 	Cost, ConnectFee                   float64
 	//	ratesInfo *RatingProfile
-}
\ No newline at end of file
+}
diff --git a/timespans/calldesc_test.go b/timespans/calldesc_test.go
index 6ff6769be..9e3054aa1 100644
--- a/timespans/calldesc_test.go
+++ b/timespans/calldesc_test.go
@@ -79,57 +79,6 @@ func TestRedisGetCost(t *testing.T) {
 	}
 }
 
-func TestApStoreRestore(t *testing.T) {	
-	d := time.Date(2012, time.February, 1, 14, 30, 1, 0, time.UTC)
-	i := &Interval{Month: time.February,
-		MonthDay:  1,
-		WeekDays:  []time.Weekday{time.Wednesday, time.Thursday},
-		StartTime: "14:30:00",
-		EndTime:   "15:00:00"}	
-	ap := ActivationPeriod{ActivationTime: d}
-	ap.AddInterval(i)
-	result := ap.store()
-	expected := "2012-02-01T14:30:01Z;2|1|3,4|14:30:00|15:00:00|0|0|0|0;"
-	if result != expected {
-		t.Errorf("Expected %q was %q", expected, result)
-	}
-	ap1 := ActivationPeriod{}
-	ap1.restore(result)
-	if ap1.ActivationTime != ap.ActivationTime {
-		t.Errorf("Expected %v was %v", ap.ActivationTime, ap1.ActivationTime)
-	}
-	i1 := ap1.Intervals[0]
-	if i1.Month != i.Month {
-		t.Errorf("Expected %q was %q", i.Month, i1.Month)	
-	}
-	if i1.MonthDay != i.MonthDay {
-		t.Errorf("Expected %q was %q", i.MonthDay, i1.MonthDay)	
-	}
-	for j,wd := range i1.WeekDays {
-		if wd != i1.WeekDays[j] {
-			t.Errorf("Expected %q was %q", i.StartTime, i1.StartTime)	
-		}	
-	}
-	if i1.StartTime != i.StartTime {
-		t.Errorf("Expected %q was %q", i.StartTime, i1.StartTime)	
-	}
-	if i1.EndTime != i.EndTime {
-		t.Errorf("Expected %q was %q", i.EndTime, i1.EndTime)	
-	}
-	if i1.Ponder != i.Ponder {
-		t.Errorf("Expected %q was %q", i.Ponder, i1.Ponder)	
-	}
-	if i1.ConnectFee != i.ConnectFee {
-		t.Errorf("Expected %q was %q", i.ConnectFee, i1.ConnectFee)	
-	}
-	if i1.Price != i.Price {
-		t.Errorf("Expected %q was %q", i.Price, i1.Price)	
-	}
-	if i1.BillingUnit != i.BillingUnit {
-		t.Errorf("Expected %q was %q", i.BillingUnit, i1.BillingUnit)	
-	}
-}
-
 func BenchmarkKyotoGetCost(b *testing.B) {
 	b.StopTimer()
 	getter, _ := NewKyotoStorage("test.kch")
@@ -216,9 +165,3 @@ func BenchmarkDecoding(b *testing.B) {
 	}
 }
 
-func BenchmarkRestore(b *testing.B) {	
-	ap1 := ActivationPeriod{}
-	for i := 0; i < b.N; i++ {
-		ap1.restore("1328106601;2|1|3,4|14:30:00|15:00:00|0|0|0|0;")
-	}
-}