Why add 左右 ("approximately") to the precisely stated time 25日17时15分左右?
It just means &quot;around&quot;.
In this case 左右 applies to the preceding &quot;17时15分&quot;, to express that the time is not exact. The writer notes that there is a margin of error or uncertainty.

当时时间25日17时15分左右
Today around 17:15 local time

The English translation also conveys the same meaning. You state a time, 5:15 PM, but also warn readers that it may be imprecise up to a certain degree.