Используйте DateDiff()
вместо -
:
=IIF(
100 / DateDiff("d", DateAdd("d", -Day(Today), Today),
DateSerial(Year(DateAdd("m", -1, Now())), 1, 1)
)
* (DateDiff("d", Today, DateSerial(Year(DateAdd("m", -1, Now())), 1, 1)) / 100) > 1,
1,
100 / DateDiff("d", DateAdd("d",-(Day(Today)), Today),
DateSerial(Year(DateAdd("m", -1, Now())), 1, 1)
)
* DateDiff("d", Today, DateSerial(Year(DateAdd("m", -1, Now())), 1, 1)) / 100
)