Solution : https://service.sap.com/sap/support/notes/110540 (SAP Service marketplace login required)
Key words :
maintain system settings sm30 view ttzcu maintain time zones sm34 view cluster vc_tzonebas maintain geographical data sm34 view cluster vc_tzonegeo, terms time zones ttzcu ttzz ttzr ttzd ttzdf ttddv ttz5 ttz5s reason, customizing solution maintain values directly, time zone customizing, 'flag entry active' button, prerequisites missing link
Related Notes :
| 1375438 | Globalization Collection Note |
| 15913 | Timezone problems (local vs. global time) |