diff --git a/sysutils.go b/sysutils.go
index 9978909..20ce26e 100644
--- a/sysutils.go
+++ b/sysutils.go
@@ -19,6 +19,10 @@ func GetDaySeconds(seconds int64, timeZone int64) int64 {
 	return ((seconds+timeZone*3600)/3600/24)*3600*24 - 3600*timeZone
 }
 
+func GetYesterDaySeconds(seconds int64, timeZone int64) int64 {
+	return ((seconds+timeZone*3600)/3600/24)*3600*24 - 3600*timeZone
+}
+
 func GetTickCount() int64 {
 	return time.Now().UnixNano() / 1e6
 }