Future Ted is telling his children the story in 2030.
The framing device of How I Met Your Mother places Ted Mosby in the future, where he recounts his romantic history and explains how he met their mother. The narration is voiced by Bob Saget, while Josh Radnor plays Ted during the events being remembered.
This future setting is important because the series frequently jumps across decades. Ted's main story begins in 2005, and later flash-forwards show milestones involving his children, his relationship with Tracy, and the aftermath of Tracy's death. The children are teenagers when the narration takes place.
A common mix-up is confusing 2030 with the years in which Ted's story occurs. The series premiered in 2005 and follows events largely from the late 2000s and early 2010s, but the storytelling frame is set in 2030. The finale also confirms that Tracy died in 2024, six years before Ted's narration.