diff --git a/src/library/archive_entry.cr b/src/library/archive_entry.cr
index 4075590..ab229af 100644
--- a/src/library/archive_entry.cr
+++ b/src/library/archive_entry.cr
@@ -52,10 +52,6 @@ class ArchiveEntry < Entry
     @zip_path
   end
 
-  def createtime : Time
-    ctime @zip_path
-  end
-
   private def sorted_archive_entries
     ArchiveFile.open @zip_path do |file|
       entries = file.entries
diff --git a/src/library/dir_entry.cr b/src/library/dir_entry.cr
index a444cb0..601431b 100644
--- a/src/library/dir_entry.cr
+++ b/src/library/dir_entry.cr
@@ -60,10 +60,6 @@ class DirEntry < Entry
     @dir_path
   end
 
-  def createtime : Time
-    ctime @dir_path
-  end
-
   def read_page(page_num)
     img = nil
     begin
diff --git a/src/library/entry.cr b/src/library/entry.cr
index 596d34d..5f19d77 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -211,7 +211,7 @@ abstract class Entry
     TitleInfo.new @book.dir do |info|
       info_da = info.date_added[@title]?
       if info_da.nil?
-        date_added = info.date_added[@title] = createtime
+        date_added = info.date_added[@title] = ctime path
         info.save
       else
         date_added = info_da
@@ -222,8 +222,6 @@ abstract class Entry
 
   abstract def path : String
 
-  abstract def createtime : Time
-
   abstract def read_page(page_num)
 
   abstract def page_dimensions