SAP 日期函数

1.计算两个时间的时间差：cl_abap_tstmp=>subtract

DATA: tstmp1 TYPE timestampl,
      tstmp2 TYPE timestampl,
      diff   TYPE tzntstmpl. " P代表秒

" 获取两个时间戳
tstmp1 = '20230911183000'.
tstmp2 = '20230911153000'.

diff = cl_abap_tstmp=>subtract(
    EXPORTING
       tstmp1 = tstmp1
       tstmp2 = tstmp2 ).

IF diff > 86000.
WRITE: '大于24 小时'.
ELSE.
WRITE: '小于24 小时'.
ENDIF.
WRITE: / diff.

其中 diff 是带符号的，如果 tstmp1 > tstmp2 , 则diff 是正数，反之负数

2.倒推过去的日期时间：START_TIME_DETERMINE

PARAMETERS: p_inter  TYPE sytabix OBLIGATORY.
CONSTANTS gc_msehi   TYPE t006-msehi    VALUE 'MIN'.

 "Date fidle
  DATA lv_start_date TYPE sy-datum.
  DATA lv_start_time TYPE sy-uzeit.

  DATA(lv_end_date) = p_datum.
  DATA(lv_end_time) = p_uzeit.


  " Get the start date and start time
  CALL FUNCTION 'START_TIME_DETERMINE'
    EXPORTING
      duration                   = p_inter
      unit                       = gc_msehi
    IMPORTING
      start_date                 = lv_start_date
      start_time                 = lv_start_time
    CHANGING
      end_date                   = lv_end_date
      end_time                   = lv_end_time
    EXCEPTIONS
      factory_calendar_not_found = 1
      date_out_of_calendar_range = 2
      date_not_valid             = 3
      unit_conversion_error      = 4
      si_unit_missing            = 5
      parameters_not_valid       = 6
      OTHERS                     = 7.
  IF sy-subrc <> 0.
* Implement suitable error handling here
    MESSAGE s022 DISPLAY LIKE gc_e.
    RETURN .
  ENDIF.

其中 p_inter 是整数的意思，unit 参数表示时间格式”时，分，秒“

如下图：