The current service-date includes billablePeriod and servicePeriod. Since these are both periods, it is not possible to search only by the start or end date.

Concern raised on Zulip: https://chat.fhir.org/#narrow/stream/204607-CARIN-IG.20for.20Blue.20Button.C2.AE/topic/service-date.20SearchParameter

Original Post (by Tushar Nair):

The SearchParameter - 'service-date' contains description : the service-date search parameter simplifies search, since a client doesn't need to know that for inpatient and outpatient institutional EOB dates they need to search by billablePeriod.period.start, for a pharmacy EOB by item.servicedDate, and for a professional and non-clinician EOB - by item.servicedPeriod.period.start.

The FHIRPath for this search parameter is ExplanationOfBenefit.billablePeriod | ExplanationOfBenefit.item.serviced, therefore it covers both the date as well as period.start and period.end.

I want to limit the user to query by only the start date , therefore I was using the following query: [base]/ExplanationOfBenefit?service-date=ge2021-04-04&service-date=le2021-04-04. This should work well ideally but as the searchparameter is also considering the Period.end date, it leads to returning resources other than the selected date in the query. e.g. the chosen date in the query above is 2021-04-04, but if we have a resource or resources in the fhir server where billablePeriod.start is less than 2021-04-04...lets say it is 2021-04-03 and the billablePeriod.end is greater than 2021-04-04 ,lets say the end date was 2021-04-08, then inspite of running the query:[base]/ExplanationOfBenefit?service-date=ge2021-04-04&service-date=le2021-04-04, it returns the resource where period.start was 2021-04-03 and period.end is 2021-04-08. Is this behavior correct, if yes then what should be the query like to limit the search scope to the input date: 2021-04-04? Also, if the description of the search parameter talks about period.start dates specifically then shouldn't we limit the lookup to the same and not extend to period.end date?