I've taken an absorbance measurements of 30 samples, each day, over 14 days. The samples are divided into two sets; with a mass of either 3 or 6 (with 15 of each).

The measurements were not taken at the same time every day; so I have them in units of hh:mm (but all the samples were run at the same time as each other).

I'm trying to run a repeated measures ANOVA of this data to determine if there is a significant difference between the two sets (3 or 6). But I'm struggling to get my head around how to input this data.

I have 30 rows; each corresponding to one sample. The absorbance values at one time point are input as a column (14 columns), with an extra column for the mass; either 3 or 6.

But how do I give these columns a time value so the data can be analysed? Or is this the wrong way to input this data?