date values can only be called once

[ebmarquez]

In the template post file, the date field can only be called once. If it is used more than once the date format string is presented.

---
layout: post
title: ToDo week of %yyy%-%mm%-%dd%
date: %yyyy%-%mm%-%dd% %hh%:%ii%
category: ToDo
author: User
tags: [tag1, tag2]
summary: Summary of the article
---

output from the template:

---
layout: post
title: ToDo week of %yyy%-01-23
date: %yyyy%-%mm%-%dd% 10:41
category: ToDo
author: User
tags: [tag1, tag2]
summary: Summary of the article
---