Solution : https://service.sap.com/sap/support/notes/110623 (SAP Service marketplace login required)
Key words :
additional key words sy-zonlo, routine reads ttzcu unlike, default time zone, previous abap routine, read table ttzcu, time zone explicitly, table ttzcu, kernel routine, entered explicitly, user profile
Related Notes :
| 81950 | Time zones: local date in dialog and in RFC |
| 15913 | Timezone problems (local vs. global time) |