added package

Author: proycon

header.sty

@@ -2,6 +2,7 @@
 \usepackage[utf8]{inputenc}
 \usepackage{hyperref}
 \usepackage{amsmath}
+\usepackage{datetime}
 \usepackage[a4paper, top=2.5cm, bottom=2.5cm, left=2cm, right=2cm]{geometry}
 \renewcommand{\familydefault}{\sfdefault}
 \hypersetup{colorlinks=true,urlcolor=blue}