My question is how to trap years less than 1900 in valid of the textbox. It seems like this year is converted to 1900 by VFP... Try to play with form and textbox which is date type.

>>Ok, here is what I found: all dates before 03/01/0000 are considered invalid dates and the message is shown. All dates with date later than 03/01/0000 including that date are considered valid dates. That's VFP native behavior.
>>
>>Do you have explanations for that?
>>
>>Thanks in advance.
>>
>
>Because before you have the 00 ( Big Bang ) day:
>

>clear
>? DATETIME(100,12,31,0,0,0)-(365*100+329)*86400
>? DATETIME(100,12,31,0,0,0)-(365*100+329)*86400-1 && look the day ! exists a little bug here, expected empty
>? DATETIME(100,12,31,0,0,0)-(365*100+330)*86400	  && the last computed datetime
>? DATETIME(100,12,31,0,0,0)-(365*100+330)*86400-1 && now the C++ routine trap the bad value
>
>minCorrectDatetime  = DATETIME(100,12,31,0,0,0)-(365*100+329)*86400
>
>minComputedDatetime = DATETIME(100,12,31,0,0,0)-(365*100+330)*86400
>* probe datetime C++ functions
>? DAY(minComputedDatetime)	,DAY(minCorrectDatetime)
>? TTOC(minComputedDatetime)	,TTOC(minCorrectDatetime)
>? DMY(minComputedDatetime)	,DMY(minCorrectDatetime)
>? MDY(minComputedDatetime)	,MDY(minCorrectDatetime)
>* NOW YOU HAVE SMASHED the limit of 03-01-0000
>? TTOD(minComputedDatetime)	,TTOD(minCorrectDatetime)
>* try on a variable
>x = TTOD(minComputedDatetime)
>? x  && not checked
>? x+0 && but this comes checked
>