Cancellation Date/Time Question

This cancellation says "Morristown PA Sept21 9:30am". How did they adjust "9:30am", was it manually? Did they turn knobs (adjust time) every minute? Also, where is the year?

I worked for the post office in the late 1950s and as I recall the date and time were on wheels in the cancel dials and the clerk running the cancel machine set them manually. The times were approximate and the time settings were dependent upon the diligence of the clerk. I don't remember time settings other than on the hour and half-hour, but that was a long time ago and there may have been a quarter-hour option.

Don

Thanks, Don.

Time/dating cancellations: I am not an expert by any means but the time noted on cancels held significance for the Post Office in their delivery standards. Before the centralization of cancelations, the early morning 9:30/10:00AM time was placed on cancels locally to reflect the letters dropped locally after the last pick-up from the day prior. The early morning time would signify that the mail piece was picked up early (when there were several drop box pick-ups daily) and put on the first dispatch to the Main Post Office for distribution, transportation (or local delivery). Time stamps of 12:PM were used to denote pick-ups that would make an early afternoon dispatch and later times (through 5:00PM-6:00PM would indicate last office dispatches. With the onset of centralized cancellations & publicized delivery standards (set by mileage)of 1-day, 2-day, and 3-day delivery, another system was used at the centralized cancelling office. AM (no hour) denoted mails received after last pick-up of the prior day and cancelled before noon. PM was used for the remainder of the day as mails came into the central location and processed. The central processing unit had a cut-off processing time for last office dispatches. Raw mails were expected to be into the processing center by a set time and through the cancellation machines. Usually around 9:30PM the dies in the cancellation machines were changed to -PM. Those pieces that made the PM cancellation were expected to make the delivery standards, those with the -PM had a day added to the time (because these pieces did not make cut off). The Postal Service set up a National, (including Alaska & Hawaii) sampling of mail (Origin, Destination Information System {ODIS]) which sampled mail at the Carrier case & Post Office Box Section, recording postmarks for time (AM, PM, -PM), date, type of indicia, and origin zip-code. (They knew the destination zip-code, it was that of the sampled office). The larger cancelling, processing & dispatch offices worked 8 million pieces in an 6-8 hour period (3:00PM to 11:00PM) Monday thru Friday (with heavy days Wednesday thru Friday). (I am sure there is some mis-information here, cuz I ain't Wikipedia)

Just to clarify, the city name is Norristown, PA (with an "N").

The year is in very small numbers between the bottom of the postmark and the killer.
In this case, off of the stamps.

Just a further note on previous post: The use of a Date-Time cancellation, was common up through 1964, (and possibly after in local cancellations). On First Day Covers postmarked with the OFFICIAL city of issues postmark, the time was set at 9:00AM. In 1964 the noting of the 9:00AM time ceased. My last issue was noted on January 10, 1964, (there could be later). The next issue I have is the Customs Postal Card which was issued 2/64 but sans the time notation in the postmark. Was there any public notification by the Post Office Department eliminating the time notation in the postmark previous to its happening???