Need Help Editing Header Feature

Theme: Llorix One Lite
Stylesheet (style.css)

This theme places a post published date on the post entry link (see image). For my use, these posts are to share specifics of local events and I’d like to be able to edit this feature to display a manually entered date (the date of the event, in this case) instead of it displaying the post publish date. I cannot edit the publish date to accomplish this because of the obvious “scheduled” dilemma run into for notice of future events.

I need help modifying this feature so that for pages that are to use a “future events” template (need to create based upon the standard/default template) a manual date can be entered.

https://drive.google.com/file/d/0BwtlGzQfSfkMVFA2MjJockNyblU/view?usp=sharing
– Image 1 – Chrome Inspect Element, Highlighting section in question. I’ve edited here to show the date I want, not the date that is auto generated (which, in this case was Feb 24).

https://drive.google.com/file/d/0BwtlGzQfSfkMWjNWY3V6bUdXejg/view?usp=sharing
– Image 2 (stylesheet)

___________________________________________

This is the section (header) in question, from the theme’s stylesheet.css

}

.post-date .post-date-day {
display: block;
color: #fff;
font-size: 31px;
font-weight: 700;
line-height: 34px;
}

.post-date .post-date-month {
display: block;
color: #fff;
font-size: 18px;
font-weight: 500;
line-height: 24px;
text-transform: uppercase;
}