analytics - Analyzing Excel Data -

i'm stuck in project need analyze data out of excel sheet. data supposed sorted datetime, because rows datetime close eachother (e.g. within minute 5 minutes) read multi of same instance , preferably copied second sheet. concretely, sheet 1 looks this:

id - datetime - ad.inf.1 - ad.inf.2 - ad.inf.3
1 - 16:06:04
2 - 18:04:34
3 - 18:04:56
4 - 18:05:06
5 - 18:16:59

somehow, i'd have identify row 2-3-4 trifold of 1 instance (as ad.inf.2-3 same, ad.inf.1 may vary) , list on sheet 2 as

id - instanceamount - ad.inf.2 - ad.inf.3
1 - 3

what best way try , realize this?