hi,
im very new to excel formulas. im just a basic user. im getting data from my finger print device in text log files . Each employee will punch-in morning punch-out for lunch, punch-in after lunch and evening punch-out.

help me to calculate monthly working time. The data are

No Mchn EnNo Name DateTime
000001 1 000000001 ERFAN 2013/09/21 14:24
000002 1 000000001 ERFAN 2013/09/21 14:24
000003 1 000000003 Hafsah 2013/11/07 15:39
000004 1 000000002 Megawati 2013/11/07 15:39
000005 1 000000001 ERFAN 2013/11/07 16:34
000006 1 000000009 abdurRahman 2013/11/07 16:40
000007 1 000000003 Hafsah 2013/11/07 16:44
000008 1 000000001 ERFAN 2013/11/07 18:28
000009 1 000000003 Hafsah 2013/11/08 08:32
000010 1 000000002 Megawati 2013/11/08 08:32
000011 1 000000004 Sarimah 2013/11/08 08:32
000012 1 000000009 abdurRahman 2013/11/08 08:36
000013 1 000000008 Rahmanmill 2013/11/08 08:44
000014 1 000000005 Amirul 2013/11/08 08:45
000015 1 000000006 Azhari 2013/11/08 08:45
000016 1 000000002 Megawati 2013/11/08 12:07
000017 1 000000003 Hafsah 2013/11/08 12:07
000018 1 000000004 Sarimah 2013/11/08 12:07
000019 1 000000005 Amirul 2013/11/08 12:10
000020 1 000000006 Azhari 2013/11/08 12:10
000021 1 000000008 Rahmanmill 2013/11/08 12:45
000022 1 000000004 Sarimah 2013/11/08 14:56
000023 1 000000002 Megawati 2013/11/08 14:58
000024 1 000000003 Hafsah 2013/11/08 14:58
000025 1 000000005 Amirul 2013/11/08 14:59
000026 1 000000009 abdurRahman 2013/11/08 14:59
000027 1 000000006 Azhari 2013/11/08 14:59
000028 1 000000008 Rahmanmill 2013/11/08 15:00
000029 1 000000001 ERFAN 2013/11/08 15:01
000030 1 000000004 Sarimah 2013/11/08 17:53
000031 1 000000003 Hafsah 2013/11/08 17:55
000032 1 000000002 Megawati 2013/11/08 17:56
000033 1 000000006 Azhari 2013/11/08 17:59
000034 1 000000005 Amirul 2013/11/08 17:59
000035 1 000000009 abdurRahman 2013/11/08 18:01
000036 1 000000008 Rahmanmill 2013/11/08 18:13
000037 1 000000004 Sarimah 2013/11/09 08:31
000038 1 000000003 Hafsah 2013/11/09 08:32
000039 1 000000002 Megawati 2013/11/09 08:32
000040 1 000000006 Azhari 2013/11/09 08:41
000041 1 000000005 Amirul 2013/11/09 08:41
000042 1 000000009 abdurRahman 2013/11/09 08:42
000043 1 000000008 Rahmanmill 2013/11/09 08:42
000044 1 000000003 Hafsah 2013/11/09 13:07
000045 1 000000002 Megawati 2013/11/09 13:08
000046 1 000000004 Sarimah 2013/11/09 13:44
000047 1 000000005 Amirul 2013/11/09 14:01
000048 1 000000006 Azhari 2013/11/09 14:02
000049 1 000000002 Megawati 2013/11/09 14:05
000050 1 000000003 Hafsah 2013/11/09 14:05
000051 1 000000008 Rahmanmill 2013/11/09 14:09
000052 1 000000004 Sarimah 2013/11/09 14:19
000053 1 000000009 abdurRahman 2013/11/09 15:05
000054 1 000000006 Azhari 2013/11/09 15:07
000055 1 000000008 Rahmanmill 2013/11/09 15:07
000056 1 000000009 abdurRahman 2013/11/09 16:08
000057 1 000000003 Hafsah 2013/11/09 18:09
000058 1 000000004 Sarimah 2013/11/09 18:10
000059 1 000000006 Azhari 2013/11/09 18:11
000060 1 000000005 Amirul 2013/11/09 18:11
000061 1 000000005 Amirul 2013/11/09 18:11
000062 1 000000009 abdurRahman 2013/11/09 18:18
000063 1 000000008 Rahmanmill 2013/11/09 18:28
000064 1 000000001 ERFAN 2013/11/09 18:42

thank you