We reconsider the role of timing and duration as cornerstone concepts in the life course perspective. While many studies consider these two concepts as naturally co-existing and complementary pieces of the life course perspective, we argue they are fundamentally in tension: the more that duration applies, the less that timing can also matter. We argue that timing is the more essential life course hypothesis, since duration per se has no referents in the life course, until a timing argument is added. We analyze married women's complete employment histories to assess the relative importance of timing vs. duration of nonemployment on current mental health. A number of specifications of both timing and duration were considered in this assessment, including the addition of co-incident events in the life course, and proximal child births and spousal unemployment, as additional ways to specify the importance of timing of job losses beyond age per se. We also consider both the context (reasons for leaving jobs) and the sequence of occurrence of events around the job exit. Our results show that, once all factors are considered, timing has long-term effects on current distress while the duration of nonemployment does not. Most of the observed effects of the earlier timing of job exits operate independently of current job status or job situation, suggesting important long-term impacts on mental health that are not mediated by selection into specific job situations or environments.