Seven experiments (total N = 3,509) and a large field dataset (N = 1,820,671) demonstrate that time periods of equal duration are not always perceived as equivalent. We find that periods feel longer when they span more time categories (e.g., hour, month). For example, periods like 1:45pm – 3:15pm and March 31st – April 6th (boundary-expanded) feel longer than, say, 1:15pm – 2:45pm and April 2nd – April 8th (boundary-compressed). Reflecting this, participants anticipated completing more work during boundary-expanded periods than equivalent boundary-compressed periods. This effect appears to result from the salience and placement of time boundaries. As a consequence, participants preferred scheduling pleasant activities for boundary-expanded and unpleasant activities for boundary-compressed periods. Moreover, participants were willing to pay more to avoid—and required more money to endure—a long wait when it was presented as boundary-expanded. Finally, data from over 1.8 million rideshare trips suggest that consumers are more likely to choose independent rides (e.g., UberX) when they are boundary-compressed when the alternative shared option (e.g., UberPool) is boundary-expanded. Together, our studies reveal that time periods feel longer when they span more boundaries, and that this phenomenon shapes consumers’ scheduling and purchasing decisions.