​Hello and thank you for your inquiry-   Please refer to the eCQI resource center for information and materials on this topic. QDM Model 5.5 ( https://ecqi.healthit.gov/sites/default/files/QDM-v5.5-Guidance-Update-May-2020-508.pdf ) provides some examples worth your consideration regarding the data-type "Encounter, Performed". Specifically, see figure 4 on page 9 for more information regarding how length of stay is calculated. The Clinical Quality Language (CQL) Style Guide V4 ( https://ecqi.healthit.gov/sites/default/files/CQL-Style-Guide-v4.pdf ) also contains examples specific to the "Global.LengthInDays" function. See page 12.   The start of the relevant period for "Encounter, Performed" looks for the encounter admission date and time. The end of the relevant period for "Encounter, Performed" looks for the encounter discharge date and time. The "Global.LengthInDays" function is equal to the number of days in the "Encounter, Performed" data type. In this case it is the discharge date minus admission date.   Global.LengthInDays(Value Interval<DateTime>) •difference in days between start of Value and end of Value   So, the "start of Value" would be the admission date, and the "end of Value" would be the discharge date. When applied to the definition you referenced in STK 3, we see the following:     "where Global."LengthInDays"(NonElectiveEncounter.relevantPeriod)<=120"   This logic will return only Non-Elective Encounters that are less than or equal to 120 days.   "and NonElectiveEncounter.relevantPeriod ends during "Measurement Period"   Finally, the logic ensures that it returns only encounters that are less than or equal 120 days during the defined measurement period.   Examples:   Assume that the measurement period is for the calendar year of 2019.   1.Patient is admitted on 12/31/2018, and is discharged on 1/5/2019. a.This encounter would not be included. It is less than or equal to 120 days, but the admission date is outside of the measurement period. 2.Patient is admitted on 1/10/19, and is discharged on 6/12/2019. a.This encounter would not be included. It is greater than 120 days long, but does occur in the measurement period. 3.Patient is admitted on 12/31/2019, and is discharged on 1/5/2020. a.This encounter would not be included. It is less than or equal to 120 days, but the discharge date is outside of the measurement period. 4.Patient is admitted on 3/1/2019, and is discharged on 3/8/2019. a.This encounter would be included. It is less than or equal to 120 days, and occurs entirely in the measurement period.​

Function is as below : ["Encounter, Performed": "Non-Elective Inpatient Encounter"] NonElectiveEncounter where Global."LengthInDays"(NonElectiveEncounter.relevantPeriod)<= 120 and NonElectiveEncounter.relevantPeriod ends during "Measurement Period" Could you please guide me calculate 120 days duration that ends in MP. Please guide with examples.