Solution : https://service.sap.com/sap/support/notes/910834 (SAP Service marketplace login required)
Key words : 
method fill_xkonh level            visibility   description instance method  private      fill xkonh iv_knumh   importing            type          knumh is_xvake   importing            type          vakevb et_xkonh   returning            type          cond_konhdb_t parameters parameter  type      optional  typingmethod  associatedtype iv_mode    importing, method fill_ykonh level            visibility   description instance method  private      fill ykonh parameters parameter  type      optional  typingmethod  associatedtype iv_mode    importing, iv_knumh   importing            type          knumh et_ykonh   returning            type          cond_konhdb_t 3, type instance attribute    private       type     cond_konhdb_t 2, level                visibility    typing, class attribute add attribute mt_ykonh, condition based tax calculation, class methods add, prerequisites program error, condition record header
Related Notes : 
       
| 1298547 | J_1B_MIGRATE_TAX_RATES: table A346, field Valid To incorrect | 
| 1015929 | Valid-to date not udpated in condition header via J1BTAX | 
| 912036 | Brazil:No transport of shortened condition validity periods | 
| 903749 | Brazil : Date of Condition record not updated via IDOC |