Specific timing instructions (when, offset, dayOfWeek, timeOfDay and code)

A dosage instruction can be tied to the specific days, dates and times, plus life events related to eating or sleeping.

Dosage.timing.repeat.when and Dosage.timing.repeat.offset

The when element ties to the regular life events of sleeping and eating, for example “C” = “event occurs at a meal” and “WAKE” = “event occurs [offset] after waking”.

An offset allows the event to be tied X minutes before or after. The offset is an unsigned integer value so different codes within the when value-set are used to define before or after.

Dosage.timing.repeat.dayOfWeek and Dosage.timing.repeat.timeOfDay

A dosage instruction can specify specific days of the week and/or times of the day using dayOfWeek and timeOfDay.


A dosage instruction can specify specific dates and times using event.


Allows a code, often a Latin abbreviation, for a timing schedule to be specified, for example, “BID” (=twice a day). It is recommended that such codes are not used when the rest of the Dosage structure is supported by the system. Instead use the structures like frequency and period so that a timing schedule can be computable.

Tags: fhir