The Recents tab found in the iPhone’s native Phone app is meant to display a running history of your incoming and outgoing phone call activity, making it easier for you to call someone back or reference a phone number if you ever needed to. Sadly, the timestamps for older phone calls tend to become less descriptive over time, showing only the date and not the timeframe.
Thankfully, a new free jailbreak tweak called ExactTimePhone by iOS developer gilshahar7 can fix this problem. As shown in the before and after screenshot examples above, this tweak makes even your oldest phone history items show a timestamp in addition to the date that it transpired.