While real-time is Twitter’s bread and butter, the company this week announced the ability to search for older tweets.

Previously limited to tweets that had been made over the past week, Twitter has started rolling out an update that allows you to search older tweets — although Twitter didn’t say how old — by hashtag or keyword.

We should note that not every single one of your tweets will be shown in your search results. Rather, it will be a selection based on a variety of metrics, such as favorites and retweets. Here’s what Twitter’s Paul Burstein had to say about it:

“We look at a variety of types of engagement, like favorites, retweets, and clicks, to determine which tweets to show. We’ll be steadily increasing this percentage over time, and ultimately, aim to surface the best content for your query.”

Earlier this week, Twitter updated its iPhone and Android apps in an attempt to simplify the way people find content. Mobile search results now return a relevant mix of tweets, photos, and accounts, all in a single stream.

It’s unknown what prompted the latest update, but it’s possible that Twitter wanted to give members better access to their tweets — although members have been able to download all of their tweets since December. Expanding the search time length could also benefit advertisers. According to marketing firm TBG Digital, advertising on search results are more effective than if they were inserted into a member’s Twitter feed.

Whatever the case, it’s a convenient update — available on mobile apps as well as Twitter.com — for advertisers, individuals, and those who just want to take a walk down memory lane.