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(More info on IBM CMOD date formats, and an example of IBM CMOD arsdate.) |
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== History == | == History == | ||
In the early 1990's when IBM CMOD was developed, two facts necessitated the IBM Content Manager OnDemand developers to use their own date formats: The high cost of data storage, and the lack of date and/or time formats in the database engines that were supported by OnDemand. | In the early 1990's when IBM CMOD was developed, two facts necessitated the IBM Content Manager OnDemand developers to use their own date formats: The high cost of data storage, and the lack of date and/or time formats in the database engines that were supported by OnDemand. The solution was to store dates as integers - representing the number of days since midnight, January 1st, 1970, UTC. If you're a UNIX or Linux user, you should recognize this date as the 'epoch' date - UNIX servers start counting the number of seconds since this date as their internal representation for dates for most operating system functions. In fact, IBM CMOD used UNIX epoch date/time as its internal date/time format up until IBM CMOD v9.5. | ||
This relationship means you can fairly easily convert between UNIX epoch date/time format, and the IBM CMOD arsdate format - simply divide by 86400 -- the number of seconds in a day. | |||
129600 / 86400 = 1.5 | |||
A UNIX time format of 129600 is noon on the second day of January, 1970. | |||
== Old Formats == | == Old Formats == | ||