In nearly every species on earth, life pulses with a day/night or circadian rhythm. In humans, these daily rhythms are driven by a genetically inherited biological clock mechanism that is present in all our cells. This mechanism regulates how we physiologically adapt to light/dark, activity/rest, and wake/sleep. However, it also influences far more than daily habits. Cardiovascular disease, obesity, diabetes and cancer have all been linked to disruption in the circadian mechanism. When the mechanism is disturbed, things go awry. In recent years there has been a flurry of research investigating how living cells keep time, and what these circadian rhythms mean for health and disease. Our research has revealed two new promising circadian strategies that benefit the treatment of cardiovascular disease. 1) Day vs. night timing of drug administration (chronotherapy) is an effective strategy that uses circadian biology to benefit treatment of heart disease. The rationale is that timing of therapy matches biologic need, which varies across 24h day/night. 2) Maintaining sleep and circadian rhythms in intensive care units is a promising non-pharmaceutical approach to improve outcomes after heart attacks. Circadian rhythms research leads directly to clinical strategies that can benefit the treatment of disease.