I got the same problem in My Benefits app( UIX01HCM SP04 , SRA007 SP05 with SAP_UI 10). I got this problem with SP03, so I upgraded to SP04. I still see the same problem with Participation start and end dates.
It shows 12/30/9999 instead of 12/31/9999. My timezone is EST in both back end and front end. OData provides correct dates. Some where in the UI libs making wrong calculation.
I already created thread for this.
Fiori My Benefits App - one day less in start and end dates
