I have a table that has four date fields & four time fields, corresponding with the stages of a job. Let's call them Stage 1, Stage 2, Stage 3 & Stage 4.

I need to ensure that the stage Stage 4 date & time >= Stage 3 date & time, stage 3 date & time >= stage 2 date & time & so on. I can validate by calculation that one date is >= to another but I can't work out how to do it in conjunction with a time.

Can anyone point me in the right direction?

Use TimeStamp ( ) to build a timestamp from the corresponding date and time fields.

btw, you might consider putting these stage fields in a child table, which lets you add more stages, if needed,

and makes such comparisons and validations easier, regardless of the number of stages. As a bonus your layout

isn't cluttered with unused fields.