Our modern astrology software contains excellent databases, but when a client was born in Illinois during a period when Daylight Savings Time was observed it can get very confusing because there was a law in Illinois in effect until 1959 which required birth times to be recorded in standard time even when daylight time was observed. So you may have a situation in which the baby book says daylight time but the birth certificate, which usually doesn’t include daylight or standard time, will be an hour off.

This often comes up with my clients and I thought it would be useful to have this information here on the blog in case others were searching online for details about this.

Here is a link to the old Time Changes in the USA book which is fortunately stored in the Internet Archive. Most of us old-timers own the book because we had to use it and you can purchase it here, but it’s also available online. https://archive.org/details/time-changes-in-usa-1966/mode/2up?q=Illinois
Beginning on page 38 of 194 you’ll see the counties with reference to table numbers and the table of daylight savings time dates for each year up until 1959 when the law changed.  In Chicago, for example, Table I applies and you’ll find that on page 38 of 194 showing us that daylight savings time was indeed in effect that summer. However, if you go to page 188 of 194 you’ll see the section about Illinois that says
The hour of birth has been recorded on Illinois birth certificates ever since the state central registry was established in 1916. Prior to July 1, 1959, United States Standard Time was used in reckoning the date and time of occurence in the preparation of official certificates of births, stillbirths and deaths, regardless of whether or not Daylight Saving Time, War Time, or any other advanced time, by whatever term known, was in effect..
Fortunately we no longer have to look all this stuff up and the software does it for us. But if your astrologer doesn’t have access to this Time Changes book, or modern software, you will get an incorrect result if you enter a birth certificate time as daylight savings time. The software will automatically produce a chart with standard time instead.
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