Need to calc start and end date from single effective date

I am trying to write SQL to calculate the start and end date from a single date called effective date for each item. Below is a idea of how my data looks. There are times when the last effective date for an item will be in the past so I want the end date for that to be a year from today. The other two items in the table example have effective dates in the future so no need to create and end date of a year from today. I have tried a few ways but always run into bad data. Below is an example of my query and the bad results select distinct tb1.itemid,tb1.EffectiveDate as startdate , case when dateadd(d,-1,tb2.EffectiveDate) < getdate() or tb2.EffectiveDate is null then getdate() +365 else dateadd(d,-1,tb2.EffectiveDate) end as enddate from #test tb1 left join #test as tb2 on (tb2.EffectiveDate > tb1.EffectiveDate or tb2.effectivedate is null) and tb2.itemid = tb1.itemid left join #test tb3 on (tb1.EffectiveDate < tb3.EffectiveDate andtb3.EffectiveDate <tb2.EffectiveDate or tb2.effectivedate is null) and tb1.itemid = tb3.itemid left join #test tb4 on tb1.effectivedate = tb4.effectivedate and tb1.itemid = tb4.itemid where tb1.itemID in (62741,62740, 65350) Results - there is an extra line for 62740 Bad Results I expect to see below since the first two items have a future end date no need to create an end date of today + 365 but the last one only has one effective date so we have to calculate the end date.