IBM Shop Dates!

	A	B	C	D	E	F	G	H	I	J	K	L	M	O	P	Q	R	S	AA
1
2
3									0 - 1.3	prev month -2		0 - 2	pull to the last week of previous month?
4	(Sheet 2 is a loose theory about one Saturday a month... or perhaps two Saturdays per month? Hmm........)							1 month = 0.77	1.3 - 2.6	prev month -1		2 - 3
5	(Well, at the moment, this sheet gets within a stones throw of about a month in terms of accuracy - individual weeks are speculative at best.)								2.6 - 3.9	1		3 - 4	first week
6	(Scroll down to row 32 to check a Shop Date, or just add it to the list underneath it.)							Loose guideline...:	3.9 - 5.2	2		5 - 6	second week
7									5.2 - 6.5	3		7 - 8	third week
8	I am officially convinced the Shop Date was their internal code for the production/working day.								6.5 - 7.8	4		8 - 9+	fourth week
9	This very loose formula can at least tell you what month and year the sub-assembly of a Model F or Model M was manufactured, and approximately what week during that month.								7.8 - 9.1	next month +1		9 - 10	push to the first week of the next month

10			Shop Date:						9.1 - 10	next month +2
11		5/29/1984 = 4829	4829	Working days since 4829	Working days/5= approximate weeks	...+ x years and y months	Approximations based on June 1984 as a base.
12	Model M Case Label Dates. These do not correlate exactly to the shop date, and are here mainly for reference. (At least two of these are from sub-assemblies not original to the keyboard they were in.)	9/18/1985	5173	344	68.8	1.323076923	(06/01/84...+ 1 year and 3.2 months)	first week of september '85?
13		8/8/1986	5406	577	115.4	2.219230769	…+ 2 years and 2.2 months.	first week of august?
14		10/1/1986	5443	614	122.8	2.361538462		third week of september?
15		10/24/1986	5461	632	126.4	2.430769231		second week of october?
16		3/23/1987	5566	737	147.4	2.834615385		second week of february?
17		6/12/1987	5628	799	159.8	3.073076923		fourth week of june?
18		7/9/1987	5645	816	163.2	3.138461538		second week of july?
19		7/23/1987	5655	826	165.2	3.176923077		fourth week of july?
20		8/26/1987	5678	849	169.8	3.265384615		third week of august?
21		10/6/1987	5711	882	176.4	3.392307692		first week of october?
22		10/12/1987	5714	885	177	3.403846154		first week of october?		birthday buddies!
23		10/13/1987	5714	885	177	3.403846154		first week of october?		birthday buddies!
24		12/28/1987	5766	937	187.4	3.603846154		first week of december?
25		1/11/1988	5787	958	191.6	3.684615385		first week of january?		christmas gap?
26		4/27/1988	5854	1025	205	3.942307692	...+ 3 years and 9.4 months.	second to third week of march?
27		7/25/1988	5919	1090	218	4.192307692	...+ 4 years and 1.9 months.	first week of august?
28		10/26/1988	5986	1157	231.4	4.45	...+ 4 years and 4.5 months.	third week of october?
29		3/22/1989	6088	1259	251.8	4.842307692	...+ 4 years and 8.4 months.	second week of february?
30		4/3/1989	6096	1267	253.4	4.873076923	...+ 4 years and 8.7 months.	fourth week of febuary?						4829	22	5/29/1984	Tuesday	4
31		11/30/1989	6270	1441	288.2	5.542307692	...+ 5 years and 5.5 months.	second week of november?						4835	23	6/5/1984	Tuesday	1
32		1/23/1990	6310	1481	296.2	5.696153846	...+ 5 years and 6.9 months.	.....second week of january? hmm.						4840	24	6/12/1984		2
33														4845	25	6/19/1984		3
34	F		5598	769	153.8	2.957692308	...+2 years and 9.6 months. Third week of March 87?			(3-3 handwritten)				4850	26	6/26/1984		4
35														4856	27	7/3/1984		1
36	F		4925	96	19.2	0.3692307692	...+3.7 months, third week of September '84? (PC-AT was released August 14th).			(3-1 handwritten)				4861	28	7/10/1984		2
37														4866	29	7/17/1984		3
38		Enter a shop date here:	4705	-124	-24.8	-0.4769230769								4871	30	7/24/1984		4
39		1/28/1986												4876	31	7/31/1984		5
40		1/28/1986	4849	20	4	0.07692307692	(...as a simple test close to the beginning, just adding 20 calendar days brings us to 6/26. .076=fourth week. 6/26/84 does fall on the fourth week of the month.)							4882	32	8/7/1984		1
41		For teh lulz...:	0	-4828	-965.6	-18.56923077	...minus 18 years and 6 months: January 1966. Pretty close... Division name changed in August '64.				hmm... 4829/250=	19.316	ok, yeah that's right...	4887	33	8/14/1984		2
42	...add to the list!:	1/28/1986	5273											4892	34	8/21/1984		3
43	F (AT)		5987	1158	231.6	4.453846154	...+4 years 4.5 months. middle of October 88? Weird, PC-AT was discontinued in April '87. They kept producing the F AT...?					(5-2 handwritten)		4897	35	8/28/1984		4
44	F (AT)		5430	601	120.2	2.311538462	Second week of September '86?							4903	36	9/4/1984		1
45	F 107 (Jan '85)		4990	161	32.2	0.6192307692	Second week of December '84? https://www.flickr.com/photos/123564336@N03/sets/72157648054292981/	1/9/1985						4908	37	9/11/1984		2
46	F (AT)		5408	579	115.8	2.226923077	1st week of August '86? https://geekhack.org/index.php?topic=40599.0			(1/3 ? handwritten, or perhaps those are initials...?)				4913	38	9/18/1984		3
47	F (AT)		5191	362	72.4	1.392307692	First week of October '85? https://geekhack.org/index.php?topic=48288.0			(3-1 handwritten)				4918	39	9/25/1984		4
48	1392560		6098	1269	253.8	4.880769231	first week of march '89? this is the silly little 50-key M with the F-style plates and M-style circuit membrane. case date is 9/2/92, so the internals sat around for a few years before getting stuffed into a case. :P	4/9/1989						4924	40	10/2/1984		1
49	F (AT)		4944	115	23	0.4423076923		11/6/1984
50			4808
51	F 107		5492	663	132.6	2.55	third week of november 86		161.4423077		86.8			4929	41	10/9/1984		2
52	1390120	5/19/1986	5346	517	103.4	1.988461538	first week of april 86			6/9/1900				4934	42	10/16/1984		3
53	131	4/26/1986	5330	501	100.2	1.926923077	first week of april 86							4939	43	10/23/1984		4
54	120	1/13/1986	5257	428	85.6	1.646153846	third week of december 85							4944	44	10/30/1984		1
55	120	2/19/1986	5283	454	90.8	1.746153846	second week of january 86							4950	45	11/6/1984		2
56	120	5/9/1986	5338	509	101.8	1.957692308	first week of april 86							4955	46	11/13/1984		3	44
57	1401	4/22/1989	6110	1281	256.2	4.926923077	first week of march 89							4960	47	11/20/1984		4
58	120	3/25/1986	5308	479	95.8	1.842307692	second week of february 86							4965	48	11/27/1984		5
59	120	5/27/1986	5354	525	105	2.019230769	last week of may 86	super close!						4971	49	12/4/1984		1
60	1401	10/30/1987	5727	898	179.6	3.453846154	third week of october 87	super close!						4976	50	12/11/1984		2
61	1401	1/6/1988	5774	945	189	3.634615385	second week of december 87							4981	51	12/18/1984		3
62	1401	5/30/1989	6138	1309	261.8	5.034615385	second week of may 89	super close!						4986	52	12/25/1984		4
63	120	12/17/1986	5502	673	134.6	2.588461538								4992	1	1/1/1985		1
64			5238	409	81.8	1.573076923								4997	2	1/8/1985		2
65	F XT	N/A	4645	-184	-36.8		October-November 1983?							5002	3	1/15/1985		3
66	F AT	???	5085	256	51.2	0.9846153846								5007	4	1/22/1985		4
67	F (XT)	Not Known	4797	-32	-6.4	-0.1230769231	6/1/84 - 1month,12days = 4/18/84 ?							5012	5	1/29/1985		5
68	F XT	Not known	4882	53	10.6	0.2038461538	7/29/84 - 2 months							5018	6	2/5/1985		1
69	F XT	Not known	5171	342	68.4	1.315384615	September '85?							5023	7	2/12/1985		2
70									0					5028	8	2/19/1985		3
71														5033	9	2/26/1985		4
72														5039	10	3/5/1985		1
73														5044	11	3/12/1985		2
74														5049	12	3/19/1985		3
75														5054	13	3/26/1985		4
76														5060	14	4/2/1985		1
77														5065	15	4/9/1985		2
78														5070	16	4/16/1985		3
79														5075	17	4/23/1985		4
80														5080	18	4/30/1985		5
81														5086	19	5/7/1985		1
82			5273											5091	20	5/14/1985		2
83			5987											5096	21	5/21/1985		3
84			5430											5101	22	5/28/1985		4
85			4990											5107	23	6/4/1985		1
86			5408											5112	24	6/11/1985		2
87			5191											5117	25	6/18/1985		3
88			6098											5122	26	6/25/1985		4
89			4944											5128	27	7/2/1985		1
90			4808											5133	28	7/9/1985		2
91			5492											5138	29	7/16/1985		3
92			5238											5143	30	7/23/1985		4
93			4645											5148	31	7/30/1985		5
94			5085											5154	32	8/6/1985		1
95			4797											5159	33	8/13/1985		2
96			4882											5164	34	8/20/1985		3
97			5171											5169	35	8/27/1985		4
98														5175	36	9/3/1985		1
99														5180	37	9/10/1985		2
100														5185	38	9/17/1985		3