Chrononutrition is the intersection between nutrition and the body’s circadian rhythms. A selfsustained molecular oscillator, composed of clock genes, is located in all cells of our body. This oscillator drives rhythmic expression of clock-controlled genes, which make up 10–20% of a tissues’ transcriptome (all the gene readouts present in a cell). This results in a nearly 24-hour rhythm, which drives circadian variations in hormone levels, enzyme activity, and cellular activity in most cells of the body. The maturation of circadian rhythms in infants takes several months. Circadian rhythmicity is demonstrated in various breastmilk components. Breastmilk is often fed to infants at a time of day different from the time it was collected. Does this mean we need to change our recommendations for feeding expressed milk? This presentation will explore why infant circadian rhythm development is important, the circadian rhythms of breastmilk components, the potential effects of consuming mismatched breastmilk, and potential interventions based on chrononutritional concepts.