What you need to do is figure out the approximate tweet ID number that was current when the phenomenon you’re studying was taking place. If you’re a regular twitterer, go to your personal timeline, find a tweet you posted on April 7th, and click on the date to get the ID of the tweet. In the early morning (GMT) of the 7th, the ID for a new tweet was roughly 1468000000 - the URL http://search.twitter.com/search?max_id=1468000000&q=%23pman&rpp=100 retrieves the first four tweets to use the tag #pman, including our Ur-tweet:
evisoft: neata, propun sa utilizam tag-ul #pman pentru mesajele din piata marii adunari nationale
My Romanian’s a little rusty, but Vitalie Eşanu appears to be suggesting we use the tag #pman - short for Piata Marii Adunari Nationale, the main square in Chisinau where the protests were slated to begin - in reference to posts about the protests. His post is timestamped 4:40am GMT, suggesting that there were at least some discussions about promoting the protests on Twitter before protesters took to the streets.