You will probably need to supply more information before someone can answer your question.
1. What data type are you using in the table field?
2. How are the sample times getting into the table field?
1: -
You could use a text data type but that would require more work than is really necessary.
You could use a date/time data type but you will eventually run into Access trying to be too helpful when formatting the display.
I would think that you should be using a double data type (preferred) because it matches exactly with the date/time data type without the display hassles (or a Long if the period can’t exceed ~ 45 days)
2: -
Internally, Access does not create date/times with a resolution greater than 1 second. Using API calls a resolution of 1 millisecond is available.
Therefore, it seems that the times are being entered into Access by some non-normal means.
So I think more information is required.
Regards,
Chris.