how to convert time

[triticale]

I am looking at intraday stock price history, and I do not quite understand the way time is expressed. Like: 20140918T153000. From this string, I am able to get date info, and I also know that 153000 represents time of the day. However, I do not know the way to converting the time to US east time.
Could there be anyone knowing what this expression is, and how to convert it?

 

[ACstudio]

Hours in a day can be expressed as 2 sets of 12 (am and pm) or 1 set of 24. So 15 is the 15th hour of the day (or 3pm.....15-12=3) the 30 is the minutes and 00 is the seconds.

 

[gc1]

Your need to know what time zone that date/time is in. If it's Chicago time (CMEgroup) add one hour to get EST (16:30), if it's UTC subtract four hours (11:30).