Despite the technical advancements in insulin pumps, the internal pump clocks do not automatically adapt for time-changing or time-zone movement.

Insulin pumps produce insulin in a bimodal fashion, with constant infusion of basal insulin and bolus insulin doses provided in quick infusion for meal cover and high blood glucose correction. Both modes of distribution are set by time, with dynamic requirements. For example, a patient can need variable basal insulin infusion levels, per daytime; usually, a person requires less basal insulin at night and during active physical activity, such as during exercise; Mealtime doses of insulin to the bolus can also differ. When it comes to the insulin requirements, insulin sensitivity or insulin resistance, each patient is different.

Effective dosing of insulin therefore relies on the right setting of the time in the insulin pump. This refers to almost all the insulin pumps required for patient use. Recently launched hybrid insulin pumps with an auto-mode insulin delivery feature that has been in used for a couple of years still has time-related glitches. Basal insulin delivery is automatic, for example, in the case of the most widely used hybrid device. Patients, however, need to remember to manually enter personal details, such as grams of carbs and current blood glucose, into the bolus calculator of the device to collect insulin bolus doses before meals. The meter makes use of preset insulin settings to carb ratios and correction factors. Furthermore, when patients are urged back into manual mode, the pump will return to function just like any other conventional pump — the internal pump clock still needs personal attention.