An approach from the point of view of what effect Daylight Saving Time may have on their war effort indicates that many individuals and even large segments of our population may properly be eliminated from consideration, thereby limiting our study to those groups whose war effort is directly and appreciably affected. For instance, thousands of individuals and groups are not engaged in war work directly or even indirectly. Their conveniences, likes, and prejudices should, therefore, not be allowed to influence decisions affecting the national war effort.
The underlying purpose of Daylight Saving time is to make better use of daylight hours because, generally speaking, man’s activities, whatever their nature, are carried on more readily and efficiently in daylight than in darkness. Other things being equal the industrial accident rate is greater during darkness than during daylight. An increase in daylight man hours of work therefore reduces accidents and resultant man hours lost, and contributes directly to the war effort. In an area subject to frequent blackouts there is a further advantage in having a maximum man-hour effort accomplished during daylight instead of during darkness when some or all production may at times be stopped altogether by a blackout. It may be said that full advantage of daylight hours can be secured by changing the time when shifts start work as well as by changing Daylight Saving Time from season to season. In practice this is not true. Changing the time for shifts to start work is disruptive of family and community routine and life because the individual is not in phase with the community. On the other hand, Daylight Saving Time on a national scale does not disrupt normal routines and life.
Adhering closely to our war effort premise, we can eliminate many individuals and groups from this study even though they are directly engaged in war work because they can easily regulate their hours of employment so as to work only during daylight hours despite the adoption of some Daylight Saving Time plan, or because the conditions of employment are such that daylight hours are not an important factor in their efficiency. Here again personal conveniences and prejudices may be so pronounced as to raise the question of morale which is an important factor in our war effort. But surely anyone engaged in war work should be willing to subordinate his personal preferences if the national effort is furthered thereby.
A number of examples will suffice to make clear that the efficiency of some war workers is not necessarily affected by the way the Daylight Saving Time question is settled. Agriculture is an industry, essential to the war effort, which has since time immemorial demanded a full day’s work during daylight regardless of the setting of the clock. Since shift work is not in question the farmer will continue to work from daylight to dark, or as much of the day as necessary, to meet his workload. The sun, rather than the clock, regulates his hours.
In industry employing three approximately equal shifts daylight saving is not a factor since work is carried on throughout the 24 hours of the day and no special advantage can be taken of the daylight hours. Also, if work is carried on in shops or factories under conditions of artificial light, advantage of daylight hours cannot be taken to increase output.
An individual working alone or industry employing but one shift is in the same position as agriculture—hours can be regulated to take advantage of daylight hours for a full day’s work regardless of what time the clock keeps.
The armed forces are not vitally affected by Daylight Saving Time. In theaters of operation the day’s work is dictated by other considerations than the kind of time in use. In training camps, etc., the daily routine can readily be adjusted to any time.
Foregoing considerations narrow the field in which full utilization of daylight hours has an important influence on output, and therefore on the war effort, to industry employing two shifts, or to three shifts where one shift is materially larger than one or both of the other two shifts. We must therefore determine how arbitrary regulation of the clock, or Daylight Saving Time, can best promote full utilization of daylight hours by industry employing two shifts of which the one is usually the larger, or three unequal shifts in which case the two larger shifts approximate a two-shift schedule in so far as utilization of daylight hours is concerned.
In the sketch graphs represent the times of Sunrise, Sunset, Beginning of Morning Twilight, and End of Evening Twilight for the calendar year 1944. It will be noted that graphs are based on War Time in effect pursuant to Public Law 403, 77th Congress, approved January 20, 1942. Graphs are plotted for Latitude 37°-00' N. and Longitude 75°- 00' W. Variations in these factors to fit various localities will, of course, not affect the principles illustrated by this study. Latitude 37°-00' N. is somewhat south of the United States industrial center but the change in the beginning of morning twilight for Latitude 42° N., for instance, would not displace the “Beginning of Morning Twilight” graph materially. Displacement east or west from a Standard Time Meridian will displace curves accordingly up to a maximum of one-half hour. It will be noted that the sketch has been reduced in height by representing the eight hours of daylight from 9:00 a.m. to 5:00 p.m. by a narrow belt. In order to make maximum use of daylight, the first (largest) shift should commence work during morning twilight. This will leave a maximum daylight period for the second shift, the first shift having had no darkness. Should there be any morning daylight hours before the main shift goes on, these will be wasted entirely in so far as productive work on the job is concerned or will be utilized only by the third (smallest) shift.
In order to accomplish the foregoing purpose the first shift must start work during the morning twilight period. In the theoretically ideal solution the time of starting work would be represented by a graph in the morning twilight zone having characteristics similar to those of the “Sunrise” and “Beginning of Morning Twilight” graphs. This is impracticable as it would require almost daily changes in time. In practice changes in time should be restricted to principal seasonal changes only. Graphs A and B, which represent starting hours for the first shift, indicate two of several acceptable solutions. Graph A follows seasonal changes closely. There are ten changes in time during the year. Its disadvantage is a frequent change in Daylight Saving Time since half-hour changes are made. Graph B uses changes of one hour in Daylight Saving Time instead. There are only four changes in time during the year. It accepts the present War Time for the periods January 1 to March 19, 1944, and October 29 to December 31, 1944.
Since too frequent changes in clock-settings would cause confusion and general dissatisfaction, Graph A will be given no further consideration. Graph B, however, appears to be an acceptable solution of our problem. In the following tabulation the Daylight Saving limes in effect if the Graph B solution is adopted are listed. The confusion and annoyances incident to a change in time are minimized if clocks are set ahead or back during the swing shift or mid-watch Sunday nights. For this reason dates ending proposed time-periods fall on Sundays. The actual setting of the clocks to the new time should take place at the same hour throughout the year, at 2:00 a.m. on Monday morning, old time.
At present Daylight Saving or War Time advances clocks one hour ahead of standard time throughout the year. This has the advantage of being permanent and uniform throughout the nation, eliminates confusion in railroad time tables, etc., especially that which is incident to local action, and effects some daylight saving during summer months. War Time, however, disregards seasonal changes which clearly must be taken into account if full use of daylight hours is to be made. Assuming 7:00 a.m. as a reasonable hour for industry to start work, it is evident from the sketch that many daylight hours are wasted during the summer and that the day shift (largest shift) is required to commence work during the winter long before there is sufficient daylight to permit efficient production without artificial light. To remedy this situation hours of commencing work would have to change seasonally, which would throw industrial workers out of phase with their community—transportation, reasonable meal hours, home routine, etc. This is even more objectionable than local action in establishing Daylight Saving Time.
In view of facts brought out by this study and in order to create a situation which will permit industry to make its greatest contribution to the war effort by utilizing daylight hours to the maximum for productive work, it is strongly urged that Public Law 403 (77th Congress) be amended so that Daylight Saving or War Time will be in accord with principles discussed herein; specifically that for the year 1944 clocks be changed from the present War Time, which is one hour ahead of standard time, as follows:
At 2:00 a.m. | Set Clocks | Resulting in Standard Time |
Mar. 20 | Ahead 1 hour | Plus 2 hours |
May 1 | Ahead 1 hour | Plus 3 hours |
Aug. 28 | Back 1 hour | Plus 2 hours |
Oct. 30 | Back 1 hour | Plus 1 hour |