An Image Data Study, based on Sales Listings

SEIKO's Liquid Crystal Digital World Time watches were produced from 1977 through 1988

This report is a work in progress. Image data is still being collected. Check back regularly for updates.

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Table of Contents


Introduction


In 1976 SEIKO wrapped up production of their mechanical world timers, replacing them with a new generation of quartz-powered, digital watches in 1977. Production of this new Digital Generation of SEIKO World Time watches would run from 1977 through at least 1988. It included iconic models, technological firsts and (until recently) a lot of generally undervalued watches.

This generation includes 6 different case designs across 5 major releases. These break out into 13 different model numbers, with 5 unique LCD layouts, at least 7 different dial frames (14 if you count different colors) and at least a dozen different bracelets.

Data Context


The data presented here is intended to assist enthusiasts, owners, collectors and sellers in making educated assumptions about original characteristics and production numbers associated with each model. It is organized to allow ongoing adjustment and addition of data, with all data detail available to anyone interested in cross checking the source information.

With 190 watches now cataloged, and assuming a production of 1,000,000 total watches, we have a margin of error of 7.103%. Despite the high level of statistical accuracy, we are still only looking at somewhere between 0.038% and 0.133% of all produced watches being accounting for in this data set.

Research Method


The dataset used here is derived from images found via internet search engines, across various online sales platforms and from various markets, including the North America, Europe, the Philippines, Malaysia and Japan. This image data is then computer analyzed to generate a base line data table of model and production year information.

With the basic image data processed, metadata information is then appended to each cataloged item, including things like dial codes, dail frame colors, case type, etc. This additional metadata was based on a human review of the images, and prone to (some) error and revision.

Tips for Exploring this Data


Here are some quick tips to make sure you get the most out of this article and its associated data.

The data presented here is dynamically generated
Repeat visits to this article may offer different and evolving detail. Keep note of the total watches cataloged. As that number changes, the summaries and detail will also change. In addition to the data presented in tables, you will also see numbers styled like this - indicating an in-line calculated / dynamic value.
The Production Summary by Year serves as a page index of sorts
Clicking on the year will scroll you to the start of the Production Detail for the selected year. Clicking on a Serial Number will open a Details view pop-up screen, with Next/Previous options to navigate through the data.

NOTE: The floating TOP button at the bottom right of the article will return you to the Summary by Year if you are in the detail, otherwise it will bring you back to the top of the article.
Be sure to visit the Model Summaries
And click the to "Expand" to view more detail, such as break-out of dial colors, specific model numbers, etc.
Throughout this article you will see icons
These are drilldown options, that will open a new tab to the Data Explorer, applying the selected filter to show the data detail. The Data Explorer has two options - viewing the data in a grid (with filter and sort options) and a Thumbnail Gallery view. The Thumbnail gallery gives you a quick view of all selected data records from the grid view.

NOTE: You can also access the Data Explorer via the Page navigation at the very top of this article.
Toggle image thumbnails on/off in Production Detail
Finally, there is an option under the main title/image of this article that allows you to toggle the page to display watch image thumbnails throughout the Production Detail by Year and Month. When activated, this can increase the page load times - as there are literally hundreds (or thousands) of images that need to be loaded.

Even if you do not show these thumbnails, you can always click on a Serial Number to view image and metadata detail.

Top-Line Data Summary


So here is what the dataset looks like.

190 Total Watches Cataloged
144 Total Months Tracked (January 1977 - December 1988)
50 Total Months w/ one or more Production Examples Found [Show me]
94 Total Months w/ zero Production Examples Found [Show me]
11 Total months where multiple watch models (cross series) were produced [Show me]

Summary by Model


Model Sum of Highest Production Numbers
found so far
Max Production
based on Serial Length
and months with at least one cataloged watch
Minimum Months Produced
based on cataloged watches
Watches Cataloged
M158-500X

1977-03 to 1979-01

44,601 169,983 17 56
A239-50XX

1978-11 to 1980-08

56,514 109,989 11 72
M159-5009

1978-07 to 1978-07

419 9,999 1 1
A230-502A

1979-12 to 1979-12

3,361 9,999 1 1
A358-50XX

1979-02 to 1980-02

30,729 99,990 10 27
A708-50XX

1984-05 to 1988-11

8,886 129,987 13 22
A718-50XX

1984-02 to 1984-07

15,207 49,995 5 11
159,717 579,942 58 190

Production Summary by Year


Click on a year in the grid below to scroll to the start of that year in the year/month production detail. Use the TOP button at the bottom right to quickly return to this summary.

Year Sum of Highest Production Numbers
found so far
Max Production
based on Serial Length
and months with at least one cataloged watch
Minimum Months Produced
based on cataloged watches
Maximum Months w/ No Production
based on cataloged watches
Watches Cataloged
1977 30,486 89,991 9 3 37
1978 15,181 79,992 8 4 18
1979 57,875 109,989 11 1 72
1980 17,716 59,994 6 6 30
1981 0 0 0 12 0
1982 0 0 0 12 0
1983 0 0 0 12 0
1984 18,983 49,995 5 7 19
1985 179 9,999 1 11 2
1986 648 29,997 3 9 3
1987 1,442 29,997 3 9 4
1988 859 39,996 4 8 5
143,369 499,950 50 106 190

Production Detail by Year and Month


WARNING: You won't find any other editorial content from here through to the end of this page. What follows is a detailed list of each cataloged serial number, grouped by year and month, with an accounting of minimum production counts (the highest Serial No-based Production number in each period). Clicking on the Full Serial Number will open a pop-up including photos and watch metadata.

1977-01 Min Production: 0 Count: 0
1977-02 Min Production: 0 Count: 0
1977-03 Min Production: 1,068 Count: 1
Year-Month Model No Full Serial Production No
1977-03 M158-5009 731068 1,068
1977-04 Min Production: 1,612 Count: 2
Year-Month Model No Full Serial Production No
1977-04 M158-5009 741601 1,601
1977-04 M158-5009 741612 1,612
1977-05 Min Production: 7,635 Count: 11
Year-Month Model No Full Serial Production No
1977-05 M158-5009 750248 248
1977-05 M158-5009 750316 316
1977-05 M158-5000 750326 326
1977-05 M158-5009 750614 614
1977-05 M158-5000 751121 1,121
1977-05 M158-5000 752219 2,219
1977-05 M158-5000 752635 2,635
1977-05 M158-5009 753061 3,061
1977-05 M158-5000 753588 3,588
1977-05 M158-5000 754376 4,376
1977-05 M158-5000 757635 7,635
1977-06 Min Production: 6,369 Count: 6
Year-Month Model No Full Serial Production No
1977-06 M158-5009 760784 784
1977-06 M158-5009 761627 1,627
1977-06 M158-5000 761837 1,837
1977-06 M158-5009 762483 2,483
1977-06 M158-5009 763033 3,033
1977-06 M158-5009 766369 6,369
1977-07 Min Production: 3,257 Count: 4
Year-Month Model No Full Serial Production No
1977-07 M158-5000 770792 792
1977-07 M158-5009 771671 1,671
1977-07 M158-5009 772844 2,844
1977-07 M158-5000 773257 3,257
1977-08 Min Production: 2,624 Count: 5
Year-Month Model No Full Serial Production No
1977-08 M158-5009 780221 221
1977-08 M158-5000 780528 528
1977-08 M158-5009 781408 1,408
1977-08 M158-5000 782549 2,549
1977-08 M158-5009 782624 2,624
1977-09 Min Production: 0 Count: 0
1977-10 Min Production: 4,036 Count: 2
Year-Month Model No Full Serial Production No
1977-10 M158-5009 702716 2,716
1977-10 M158-5009 704036 4,036
1977-11 Min Production: 1,755 Count: 3
Year-Month Model No Full Serial Production No
1977-11 M158-5000 7N0665 665
1977-11 M158-5009 7N1033 1,033
1977-11 M158-5009 7N1755 1,755
1977-12 Min Production: 2,130 Count: 3
Year-Month Model No Full Serial Production No
1977-12 M158-5009 7D1569 1,569
1977-12 M158-5009 7D1883 1,883
1977-12 M158-5009 7D2130 2,130
1978-01 Min Production: 4,001 Count: 2
Year-Month Model No Full Serial Production No
1978-01 M158-5009 810437 437
1978-01 M158-5009 814001 4,001
1978-02 Min Production: 1,200 Count: 1
Year-Month Model No Full Serial Production No
1978-02 M158-5009 821200 1,200
1978-03 Min Production: 2,757 Count: 3
Year-Month Model No Full Serial Production No
1978-03 M158-5009 830105 105
1978-03 M158-5009 831877 1,877
1978-03 M158-5009 832757 2,757
1978-04 Min Production: 0 Count: 0
1978-05 Min Production: 0 Count: 0
1978-06 Min Production: 0 Count: 0
1978-07 Min Production: 419 Count: 1
Year-Month Model No Full Serial Production No
1978-07 M159-5009 870419 419
1978-08 Min Production: 1,137 Count: 3
Year-Month Model No Full Serial Production No
1978-08 M158-5009 880479 479
1978-08 M158-5000 880746 746
1978-08 M158-5009 881137 1,137
1978-09 Min Production: 961 Count: 2
Year-Month Model No Full Serial Production No
1978-09 M158-5009 890062 62
1978-09 M158-5000 890961 961
1978-10 Min Production: 660 Count: 1
Year-Month Model No Full Serial Production No
1978-10 M158-5009 800660 660
1978-11 Min Production: 4,046 Count: 5
Year-Month Model No Full Serial Production No
1978-11 M158-5000 8N0136 136
1978-11 M158-5000 8N1153 1,153
1978-11 M158-5000 8N1195 1,195
1978-11 M158-5000 8N2067 2,067
1978-11 A239-5000 8N4046 4,046
1978-12 Min Production: 0 Count: 0
1979-01 Min Production: 1,332 Count: 3
Year-Month Model No Full Serial Production No
1979-01 M158-5009 910190 190
1979-01 M158-5009 910978 978
1979-01 M158-5009 911332 1,332
1979-02 Min Production: 3,124 Count: 1
Year-Month Model No Full Serial Production No
1979-02 A358-5000 923124 3,124
1979-03 Min Production: 0 Count: 0
1979-04 Min Production: 4,695 Count: 7
Year-Month Model No Full Serial Production No
1979-04 A358-5000 941839 1,839
1979-04 A358-5000 942190 2,190
1979-04 A358-5000 942831 2,831
1979-04 A358-5000 943184 3,184
1979-04 A358-5000 943969 3,969
1979-04 A358-5000 944644 4,644
1979-04 A358-5000 944695 4,695
1979-05 Min Production: 281 Count: 2
Year-Month Model No Full Serial Production No
1979-05 A358-5000 950264 264
1979-05 A358-5009 950281 281
1979-06 Min Production: 2,538 Count: 4
Year-Month Model No Full Serial Production No
1979-06 A358-5000 960282 282
1979-06 A358-5000 960345 345
1979-06 A358-5000 961388 1,388
1979-06 A358-5000 962538 2,538
1979-07 Min Production: 5,018 Count: 4
Year-Month Model No Full Serial Production No
1979-07 A358-5009 970491 491
1979-07 A239-5000 971816 1,816
1979-07 A358-5000 973056 3,056
1979-07 A358-5000 975018 5,018
1979-08 Min Production: 7,704 Count: 5
Year-Month Model No Full Serial Production No
1979-08 A358-5000 980409 409
1979-08 A358-5000 980589 589
1979-08 A358-5000 981235 1,235
1979-08 A358-5000 986147 6,147
1979-08 A358-5000 987704 7,704
1979-09 Min Production: 9,413 Count: 11
Year-Month Model No Full Serial Production No
1979-09 A239-5020 990295 295
1979-09 A358-5000 991356 1,356
1979-09 A239-5020 992922 2,922
1979-09 A358-5000 993095 3,095
1979-09 A239-5020 993272 3,272
1979-09 A239-502A 994284 4,284
1979-09 A239-502A 994965 4,965
1979-09 A239-5020 995104 5,104
1979-09 A239-502A 997303 7,303
1979-09 A239-502A 999149 9,149
1979-09 A239-502A 999413 9,413
1979-10 Min Production: 5,704 Count: 6
Year-Month Model No Full Serial Production No
1979-10 A239-5020 901674 1,674
1979-10 A239-5020 901944 1,944
1979-10 A239-5020 903367 3,367
1979-10 A239-502A 904908 4,908
1979-10 A239-5000 904949 4,949
1979-10 A239-5000 905704 5,704
1979-11 Min Production: 8,456 Count: 18
Year-Month Model No Full Serial Production No
1979-11 A239-5020 9N0293 293
1979-11 A239-502A 9N0433 433
1979-11 A239-5000 9N0502 502
1979-11 A239-5000 9N0594 594
1979-11 A239-502A 9N0658 658
1979-11 A239-502A 9N0673 673
1979-11 A239-5000 9N0721 721
1979-11 A239-502A 9N1167 1,167
1979-11 A239-502A 9N1414 1,414
1979-11 A239-5010 9N1889 1,889
1979-11 A239-5000 9N2238 2,238
1979-11 A239-5010 9N3609 3,609
1979-11 A239-5010 9N3907 3,907
1979-11 A239-5010 9N3914 3,914
1979-11 A239-5010 9N6067 6,067
1979-11 A239-502A 9N6663 6,663
1979-11 A239-5000 9N6780 6,780
1979-11 A239-5000 9N8456 8,456
1979-12 Min Production: 9,610 Count: 11
Year-Month Model No Full Serial Production No
1979-12 A239-5020 9D0043 43
1979-12 A239-5010 9D0898 898
1979-12 A239-5000 9D0900 900
1979-12 A239-502A 9D1318 1,318
1979-12 A239-5020 9D2019 2,019
1979-12 A239-502A 9D2124 2,124
1979-12 A230-502A 9D3361 3,361
1979-12 A358-5000 9D3590 3,590
1979-12 A239-502A 9D5686 5,686
1979-12 A239-502A 9D9529 9,529
1979-12 A239-502A 9D9610 9,610
1980-01 Min Production: 8,125 Count: 16
Year-Month Model No Full Serial Production No
1980-01 A358-5000 010437 437
1980-01 A239-502A 011024 1,024
1980-01 A239-5020 011189 1,189
1980-01 A239-502A 011227 1,227
1980-01 A239-5020 011483 1,483
1980-01 A239-502A 011725 1,725
1980-01 A239-502A 011991 1,991
1980-01 A239-5020 013554 3,554
1980-01 A239-5020 013607 3,607
1980-01 A239-502A 014035 4,035
1980-01 A239-5020 014384 4,384
1980-01 A239-502A 014895 4,895
1980-01 A239-502A 015608 5,608
1980-01 A239-5020 016343 6,343
1980-01 A239-502A 017233 7,233
1980-01 A239-5020 018125 8,125
1980-02 Min Production: 247 Count: 1
Year-Month Model No Full Serial Production No
1980-02 A358-5000 020247 247
1980-03 Min Production: 6,389 Count: 5
Year-Month Model No Full Serial Production No
1980-03 A239-5020 031617 1,617
1980-03 A239-5009 031808 1,808
1980-03 A239-5020 031892 1,892
1980-03 A239-502A 035999 5,999
1980-03 A239-502A 036389 6,389
1980-04 Min Production: 2,803 Count: 6
Year-Month Model No Full Serial Production No
1980-04 A239-5009 040131 131
1980-04 A239-5009 040682 682
1980-04 A239-5009 040770 770
1980-04 A239-5009 041317 1,317
1980-04 A239-5009 041645 1,645
1980-04 A239-5009 042803 2,803
1980-05 Min Production: 80 Count: 1
Year-Month Model No Full Serial Production No
1980-05 A239-5009 050080 80
1980-06 Min Production: 0 Count: 0
1980-07 Min Production: 0 Count: 0
1980-08 Min Production: 72 Count: 1
Year-Month Model No Full Serial Production No
1980-08 A239-5020 080072 72
1980-09 Min Production: 0 Count: 0
1980-10 Min Production: 0 Count: 0
1980-11 Min Production: 0 Count: 0
1980-12 Min Production: 0 Count: 0
1981-01 Min Production: 0 Count: 0
1981-02 Min Production: 0 Count: 0
1981-03 Min Production: 0 Count: 0
1981-04 Min Production: 0 Count: 0
1981-05 Min Production: 0 Count: 0
1981-06 Min Production: 0 Count: 0
1981-07 Min Production: 0 Count: 0
1981-08 Min Production: 0 Count: 0
1981-09 Min Production: 0 Count: 0
1981-10 Min Production: 0 Count: 0
1981-11 Min Production: 0 Count: 0
1981-12 Min Production: 0 Count: 0
1982-01 Min Production: 0 Count: 0
1982-02 Min Production: 0 Count: 0
1982-03 Min Production: 0 Count: 0
1982-04 Min Production: 0 Count: 0
1982-05 Min Production: 0 Count: 0
1982-06 Min Production: 0 Count: 0
1982-07 Min Production: 0 Count: 0
1982-08 Min Production: 0 Count: 0
1982-09 Min Production: 0 Count: 0
1982-10 Min Production: 0 Count: 0
1982-11 Min Production: 0 Count: 0
1982-12 Min Production: 0 Count: 0
1983-01 Min Production: 0 Count: 0
1983-02 Min Production: 0 Count: 0
1983-03 Min Production: 0 Count: 0
1983-04 Min Production: 0 Count: 0
1983-05 Min Production: 0 Count: 0
1983-06 Min Production: 0 Count: 0
1983-07 Min Production: 0 Count: 0
1983-08 Min Production: 0 Count: 0
1983-09 Min Production: 0 Count: 0
1983-10 Min Production: 0 Count: 0
1983-11 Min Production: 0 Count: 0
1983-12 Min Production: 0 Count: 0
1984-01 Min Production: 0 Count: 0
1984-02 Min Production: 5,376 Count: 2
Year-Month Model No Full Serial Production No
1984-02 A718-5010 425274 5,274
1984-02 A718-5010 425376 5,376
1984-03 Min Production: 0 Count: 0
1984-04 Min Production: 7,568 Count: 2
Year-Month Model No Full Serial Production No
1984-04 A718-5030 440069 69
1984-04 A718-5010 447568 7,568
1984-05 Min Production: 3,512 Count: 11
Year-Month Model No Full Serial Production No
1984-05 A708-5000 450024 24
1984-05 A718-5030 450306 306
1984-05 A718-5030 450485 485
1984-05 A718-5030 450488 488
1984-05 A708-5000 450643 643
1984-05 A718-5030 451071 1,071
1984-05 A708-5000 452064 2,064
1984-05 A708-5000 452408 2,408
1984-05 A708-5000 452640 2,640
1984-05 A708-5000 453286 3,286
1984-05 A708-5000 453512 3,512
1984-06 Min Production: 2,246 Count: 3
Year-Month Model No Full Serial Production No
1984-06 A718-5030 460636 636
1984-06 A718-5030 460911 911
1984-06 A708-5000 462246 2,246
1984-07 Min Production: 281 Count: 1
Year-Month Model No Full Serial Production No
1984-07 A718-5030 470281 281
1984-08 Min Production: 0 Count: 0
1984-09 Min Production: 0 Count: 0
1984-10 Min Production: 0 Count: 0
1984-11 Min Production: 0 Count: 0
1984-12 Min Production: 0 Count: 0
1985-01 Min Production: 0 Count: 0
1985-02 Min Production: 0 Count: 0
1985-03 Min Production: 0 Count: 0
1985-04 Min Production: 0 Count: 0
1985-05 Min Production: 179 Count: 2
Year-Month Model No Full Serial Production No
1985-05 A708-5000 550141 141
1985-05 A708-5000 550179 179
1985-06 Min Production: 0 Count: 0
1985-07 Min Production: 0 Count: 0
1985-08 Min Production: 0 Count: 0
1985-09 Min Production: 0 Count: 0
1985-10 Min Production: 0 Count: 0
1985-11 Min Production: 0 Count: 0
1985-12 Min Production: 0 Count: 0
1986-01 Min Production: 0 Count: 0
1986-02 Min Production: 0 Count: 0
1986-03 Min Production: 215 Count: 1
Year-Month Model No Full Serial Production No
1986-03 A708-5000 630215 215
1986-04 Min Production: 0 Count: 0
1986-05 Min Production: 0 Count: 0
1986-06 Min Production: 0 Count: 0
1986-07 Min Production: 0 Count: 0
1986-08 Min Production: 0 Count: 0
1986-09 Min Production: 0 Count: 0
1986-10 Min Production: 0 Count: 0
1986-11 Min Production: 283 Count: 1
Year-Month Model No Full Serial Production No
1986-11 A708-5000 6N0283 283
1986-12 Min Production: 150 Count: 1
Year-Month Model No Full Serial Production No
1986-12 A708-5000 6D0150 150
1987-01 Min Production: 0 Count: 0
1987-02 Min Production: 0 Count: 0
1987-03 Min Production: 76 Count: 1
Year-Month Model No Full Serial Production No
1987-03 A708-5000 730076 76
1987-04 Min Production: 228 Count: 2
Year-Month Model No Full Serial Production No
1987-04 A708-5000 740215 215
1987-04 A708-5000 740228 228
1987-05 Min Production: 0 Count: 0
1987-06 Min Production: 0 Count: 0
1987-07 Min Production: 0 Count: 0
1987-08 Min Production: 0 Count: 0
1987-09 Min Production: 0 Count: 0
1987-10 Min Production: 0 Count: 0
1987-11 Min Production: 1,138 Count: 1
Year-Month Model No Full Serial Production No
1987-11 A708-5000 7N1138 1,138
1987-12 Min Production: 0 Count: 0
1988-01 Min Production: 0 Count: 0
1988-02 Min Production: 0 Count: 0
1988-03 Min Production: 0 Count: 0
1988-04 Min Production: 0 Count: 0
1988-05 Min Production: 193 Count: 1
Year-Month Model No Full Serial Production No
1988-05 A708-5000 850193 193
1988-06 Min Production: 218 Count: 1
Year-Month Model No Full Serial Production No
1988-06 A708-5000 860218 218
1988-07 Min Production: 0 Count: 0
1988-08 Min Production: 0 Count: 0
1988-09 Min Production: 376 Count: 1
Year-Month Model No Full Serial Production No
1988-09 A708-5000 890376 376
1988-10 Min Production: 0 Count: 0
1988-11 Min Production: 72 Count: 2
Year-Month Model No Full Serial Production No
1988-11 A708-5000 8N0014 14
1988-11 A708-5000 8N0072 72
1988-12 Min Production: 0 Count: 0