The aim of this study was to examine developmental differences in autobiographical memory using a novel test that assesses its semantic and episodic subcomponents. Forty-two children aged 7-13 years were asked to recall semantic information and episodic events from three different time periods (current school year, last school year, and previous school years). For the recalls of all events, sense of remembering or sense of just knowing was measured via the Remember/Know paradigm. Age-related differences were observed for episodic autobiographical memory whereas semantic autobiographical memory was characterized by a relative developmental invariance. The increase with age was also found in the number of "Remember" responses and their justification in terms of the actual contextual information retrieved-factual, spatial, and, more especially, temporal details. These findings highlight developmental differences between the episodic and semantic subcomponents of autobiographical memory and support the view that mental 'time travel' through subjective time, which allows one to re-experience the past through self-awareness, is the last feature of autobiographical memory to become fully operational.