Travel management module Table field ACCDT in ptrv_perio table

Hi ,

This is in Travel management . I am trying to understand how this field is being populated when i used PR05

Transaction .For example i settle a trip and the trip date is saved in Table PTRV_PERIO .

For certain trips i am getting latest dates where as for certain trips i am getting old date copied.

For example trip number 100077795 has new recent settled date in ACCDT   .

Incase of another trip number of  different personal number has oldest settled date copied .I am not seeing new settled date .

I am unable  understand  why the old date is  getting copied and what are the behind scenes .

Can please someone explain why this old date is not being updated and is getting copied  .

Thanks,

Pradeep.