Merging Semi-Duplicate Records & Deleting Duplicates

[Ark68]

Hello all,

Please consider this sample database ...

Excel Workbook
	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P
1	REC_ID	DATE	CONTRACT #	AMMNT	TYPE	EVENT	CUSTOMER	CITY	ADDRESS	FAC_CONCATENATE	TYPE	UNIT	CLASS	STARTS	ENDS	DUP_FLAG
2		7/6/2015	70843					Memphis	21 Brighton St.	7084321 Brighton St.			A	6:00 PM	8:30 PM
3		7/6/2015	70843					Memphis	34 Weston Ave.	7084334 Weston Ave.			A	6:00 PM	8:30 PM
4		7/6/2015	70843					Memphis	355 Eastern Ave.	70843355 Eastern Ave.			A	6:00 PM	8:30 PM
5		7/6/2015	176288					Memphis	15 Main St.	17628815 Main St.			B	6:30 PM	7:15 PM
6		7/6/2015	176288					Memphis	65 Main St.	17628865 Main St.			B	5:30 PM	7:15 PM
7		7/6/2015	176288					Memphis	133 Main St.	176288133 Main St.			B	6:30 PM	7:15 PM
8		7/6/2015	176288					Memphis	566 Main St.	176288566 Main St.			B	6:30 PM	7:15 PM
9		7/6/2015	71067					Memphis	23 Greenfield Ave.	7106723 Greenfield Ave.			B	6:30 PM	8:00 PM
10		7/6/2015	71067					Memphis	1988 Wilson Ave.	710671988 Wilson Ave.			B	6:30 PM	8:00 PM
11		7/6/2015	71067					Memphis	12 Glen Forrest Blvd.	7106712 Glen Forrest Blvd.			B	6:30 PM	8:00 PM
12		7/6/2015	71067					Memphis	265 Lexington Crt.	71067265 Lexington Crt.			A	6:30 PM	9:30 PM
13		7/6/2015	71067					Memphis	97 Oriole Blvd.	7106797 Oriole Blvd.			A	6:30 PM	9:30 PM
14		7/6/2015	71539					Memphis	2001 Millenium Dr.	715392001 Millenium Dr.			A	7:00 PM	9:00 PM
15		7/6/2015	71539					Memphis	1 Old Oak Dr.	715391 Old Oak Dr.			A	7:00 PM	9:00 PM
16		7/6/2015	176288					Memphis	15 Main St.	17628815 Main St.			B	7:15 PM	8:00 PM
17		7/6/2015	176288					Memphis	65 Main St.	17628865 Main St.			B	7:15 PM	8:00 PM
18		7/6/2015	176288					Memphis	133 Main St.	176288133 Main St.			B	7:15 PM	8:00 PM
19		7/6/2015	176288					Memphis	566 Main St.	176288566 Main St.			B	7:15 PM	8:00 PM
20		7/6/2015	71182					Memphis	66 Fairway Rd.	7118266 Fairway Rd.			A	9:00 PM	11:00 PM
21		7/6/2015	71694					Memphis	2001 Millenium Dr.	716942001 Millenium Dr.			A	9:00 PM	11:00 PM
22		7/6/2015	71933					Memphis	1 Old Oak Dr.	719331 Old Oak Dr.			A	9:00 PM	11:00 PM
23		7/6/2015	71506					Dallas	988 Marsland Dr.	71506988 Marsland Dr.			B	5:30 PM	8:30 PM
24		7/6/2015	71134					Los Angeles	5 Spruce St.	711345 Spruce St.			B	9:30 AM	11:30 AM
25		7/6/2015	176288					Memphis	15 Main St.	17628815 Main St.			B	8:15 PM	9:15 PM
26		7/6/2015	176288					Memphis	65 Main St.	17628865 Main St.			B	8:00 PM	9:15 PM
27		7/6/2015	176288					Memphis	133 Main St.	176288133 Main St.			B	8:00 PM	9:15 PM
28		7/6/2015	176288					Memphis	566 Main St.	176288566 Main St.			B	8:00 PM	9:15 PM
29		7/6/2015	176288					Memphis	65 Main St.	17628865 Main St.			B	9:15 PM	11:00 PM
30		7/6/2015	176288					Memphis	566 Main St.	176288566 Main St.			B	8:00 PM	11:00 PM
CORE

I have been struggling to find and adapt code that will allow me to:
a) eliminate duplicate records (where values in columns C, N and O are equal)
b) merge semi-duplicate records into one (where values in column C are equal, but values in column O are within 15 minutes of the value in column N.)

The sample above does not have instances where situation A occurs, but basically, one of the two duplicates can be deleted.

There are four examples of scenario b:
Rows 5, 16 and 25 are semi-duplicates of each other with different times (column N and O)
Rows 6, 17, 26 and 29 are semi-duplicates of each other
Rows 7, 18, 27, and rows 8, 19, 28 and 30 are duplicate sets respectively.

I would like to merge each individual set into one record in which the start time is the lowest of the start time values in the set, and the end time is the highest value of the end times in the set. The data would be condensed as such:

Excel Workbook
	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P
1	REC_ID	DATE	CONTRACT #	AMMNT	TYPE	EVENT	CUSTOMER	CITY	ADDRESS	FAC_CONCATENATE	TYPE	UNIT	CLASS	STARTS	ENDS	DUP_FLAG
2		7/6/2015	176288					Memphis	15 Main St.	17628815 Main St.			B	6:30 PM	9:15 PM
3		7/6/2015	176288					Memphis	65 Main St.	17628865 Main St.			B	5:30 PM	11:00 PM
4		7/6/2015	176288					Memphis	133 Main St.	176288133 Main St.			B	6:30 PM	9:15 PM
5		7/6/2015	176288					Memphis	566 Main St.	176288566 Main St.			B	6:30 PM	11:00 PM
CORE

I would be most grateful for any suggestions, direction or resources to assist in overcoming this challenge. Thank you for all in advance.