diff --git a/core/env/provider.go b/core/env/provider.go
index 969771b4..a264428f 100644
--- a/core/env/provider.go
+++ b/core/env/provider.go
@@ -91,6 +91,10 @@ type StoreProvider interface {
 	// QueryTableList returns a list tables in Documize database.
 	QueryTableList() string
 
+	// QueryDateInterval returns provider specific
+	// interval style date SQL.
+	QueryDateInterval(days int64) string
+
 	// JSONEmpty returns empty SQL JSON object.
 	// Typically used as 2nd parameter to COALESCE().
 	JSONEmpty() string
diff --git a/domain/document/export.go b/domain/document/export.go
index 890b9894..f1a06e4a 100644
--- a/domain/document/export.go
+++ b/domain/document/export.go
@@ -52,6 +52,8 @@ func BuildExport(ctx domain.RequestContext, s store.Store, spec exportSpec) (htm
 			if e == nil {
 				content.WriteString(c)
 				toc = append(toc, t...)
+			} else {
+				fmt.Println("export.space", err)
 			}
 		}
 
@@ -60,6 +62,8 @@ func BuildExport(ctx domain.RequestContext, s store.Store, spec exportSpec) (htm
 		if e == nil {
 			content.WriteString(c)
 			toc = append(toc, t...)
+		} else {
+			fmt.Println("export.category", err)
 		}
 
 	case "document":
@@ -67,6 +71,8 @@ func BuildExport(ctx domain.RequestContext, s store.Store, spec exportSpec) (htm
 		if e == nil {
 			content.WriteString(c)
 			toc = append(toc, t...)
+		} else {
+			fmt.Println("export.document", err)
 		}
 	}
 
diff --git a/edition/storage/mysql.go b/edition/storage/mysql.go
index d82e58db..cb6a14bf 100644
--- a/edition/storage/mysql.go
+++ b/edition/storage/mysql.go
@@ -298,6 +298,12 @@ func (p MySQLProvider) QueryTableList() string {
         WHERE TABLE_SCHEMA = '` + p.DatabaseName() + `' AND TABLE_TYPE='BASE TABLE'`
 }
 
+// QueryDateInterval returns provider specific interval style
+// date SQL.
+func (p MySQLProvider) QueryDateInterval(days int64) string {
+	return fmt.Sprintf("DATE(NOW()) - INTERVAL %d DAY", days)
+}
+
 // JSONEmpty returns empty SQL JSON object.
 // Typically used as 2nd parameter to COALESCE().
 func (p MySQLProvider) JSONEmpty() string {
diff --git a/edition/storage/postgresql.go b/edition/storage/postgresql.go
index 14f318f6..0eef459d 100644
--- a/edition/storage/postgresql.go
+++ b/edition/storage/postgresql.go
@@ -263,6 +263,12 @@ func (p PostgreSQLProvider) QueryTableList() string {
         WHERE table_type='BASE TABLE' AND table_schema NOT IN ('pg_catalog', 'information_schema') AND table_catalog='%s'`, p.DatabaseName())
 }
 
+// QueryDateInterval returns provider specific interval style
+// date SQL.
+func (p PostgreSQLProvider) QueryDateInterval(days int64) string {
+	return fmt.Sprintf("DATE(NOW()) - INTERVAL '%d day'", days)
+}
+
 // JSONEmpty returns empty SQL JSON object.
 // Typically used as 2nd parameter to COALESCE().
 func (p PostgreSQLProvider) JSONEmpty() string {