SolmanacLearn

Equation of time, 1923

Every day of 1923 at 12:00 UT: how far a sundial runs ahead of the clock (early) or behind it (late), the Sun’s declination, and how much the day from one solar noon to the next differs from 24 hours.

The sundial runs furthest ahead around Nov 4, by 16 min 22 s, and furthest behind aroundFeb 12, by 14 min 24 s.

January

DateSundialDeclinationSolar day
Mon, Jan 13:21 late23.06° S+28.6 s
Tue, Jan 2Perihelion3:49 late22.98° S+28.3 s
Wed, Jan 34:17 late22.89° S+27.9 s
Thu, Jan 44:45 late22.80° S+27.5 s
Fri, Jan 55:12 late22.70° S+27.1 s
Sat, Jan 65:39 late22.58° S+26.7 s
Sun, Jan 76:05 late22.46° S+26.2 s
Mon, Jan 86:31 late22.34° S+25.8 s
Tue, Jan 96:56 late22.21° S+25.2 s
Wed, Jan 107:21 late22.07° S+24.7 s
Thu, Jan 117:46 late21.92° S+24.1 s
Fri, Jan 128:10 late21.76° S+23.5 s
Sat, Jan 138:33 late21.60° S+22.9 s
Sun, Jan 148:56 late21.43° S+22.3 s
Mon, Jan 159:18 late21.26° S+21.6 s
Tue, Jan 169:39 late21.07° S+21.0 s
Wed, Jan 1710:00 late20.88° S+20.3 s
Thu, Jan 1810:20 late20.69° S+19.6 s
Fri, Jan 1910:39 late20.49° S+18.9 s
Sat, Jan 2010:58 late20.28° S+18.1 s
Sun, Jan 2111:16 late20.06° S+17.4 s
Mon, Jan 2211:33 late19.84° S+16.6 s
Tue, Jan 2311:49 late19.61° S+15.8 s
Wed, Jan 2412:04 late19.38° S+15.1 s
Thu, Jan 2512:19 late19.14° S+14.3 s
Fri, Jan 2612:33 late18.89° S+13.5 s
Sat, Jan 2712:46 late18.64° S+12.7 s
Sun, Jan 2812:58 late18.39° S+11.9 s
Mon, Jan 2913:10 late18.12° S+11.1 s
Tue, Jan 3013:20 late17.86° S+10.2 s
Wed, Jan 3113:30 late17.58° S+9.4 s

February

DateSundialDeclinationSolar day
Thu, Feb 113:39 late17.30° S+8.6 s
Fri, Feb 213:47 late17.02° S+7.8 s
Sat, Feb 313:54 late16.73° S+7.0 s
Sun, Feb 4February Cross-Quarter14:01 late16.44° S+6.1 s
Mon, Feb 514:06 late16.14° S+5.3 s
Tue, Feb 614:11 late15.84° S+4.5 s
Wed, Feb 714:15 late15.53° S+3.7 s
Thu, Feb 814:18 late15.22° S+2.9 s
Fri, Feb 914:21 late14.90° S+2.1 s
Sat, Feb 1014:23 late14.58° S+1.3 s
Sun, Feb 1114:24 late14.26° S+0.5 s
Mon, Feb 12Great Latesun14:24 late13.93° S−0.2 s
Tue, Feb 1314:23 late13.60° S−1.0 s
Wed, Feb 1414:22 late13.26° S−1.7 s
Thu, Feb 1514:20 late12.93° S−2.5 s
Fri, Feb 1614:17 late12.58° S−3.2 s
Sat, Feb 1714:14 late12.24° S−3.9 s
Sun, Feb 1814:10 late11.89° S−4.6 s
Mon, Feb 1914:05 late11.53° S−5.3 s
Tue, Feb 2013:59 late11.18° S−6.0 s
Wed, Feb 2113:53 late10.82° S−6.7 s
Thu, Feb 2213:46 late10.46° S−7.3 s
Fri, Feb 2313:38 late10.10° S−7.9 s
Sat, Feb 2413:30 late9.73° S−8.6 s
Sun, Feb 2513:21 late9.36° S−9.2 s
Mon, Feb 2613:12 late8.99° S−9.7 s
Tue, Feb 2713:02 late8.62° S−10.3 s
Wed, Feb 2812:51 late8.24° S−10.8 s

March

DateSundialDeclinationSolar day
Thu, Mar 112:40 late7.86° S−11.4 s
Fri, Mar 212:28 late7.48° S−11.9 s
Sat, Mar 312:16 late7.10° S−12.4 s
Sun, Mar 412:03 late6.72° S−12.9 s
Mon, Mar 511:50 late6.33° S−13.3 s
Tue, Mar 611:36 late5.95° S−13.8 s
Wed, Mar 711:22 late5.56° S−14.2 s
Thu, Mar 811:08 late5.17° S−14.6 s
Fri, Mar 910:53 late4.78° S−15.0 s
Sat, Mar 1010:38 late4.39° S−15.3 s
Sun, Mar 1110:22 late4.00° S−15.7 s
Mon, Mar 1210:07 late3.61° S−16.0 s
Tue, Mar 139:50 late3.22° S−16.3 s
Wed, Mar 149:34 late2.82° S−16.6 s
Thu, Mar 159:17 late2.43° S−16.8 s
Fri, Mar 169:01 late2.03° S−17.1 s
Sat, Mar 178:43 late1.64° S−17.3 s
Sun, Mar 188:26 late1.24° S−17.5 s
Mon, Mar 198:09 late0.85° S−17.7 s
Tue, Mar 207:51 late0.45° S−17.8 s
Wed, Mar 21March Equinox7:33 late0.06° S−17.9 s
Thu, Mar 227:15 late0.34° N−18.1 s
Fri, Mar 236:57 late0.73° N−18.2 s
Sat, Mar 246:39 late1.13° N−18.2 s
Sun, Mar 256:21 late1.52° N−18.3 s
Mon, Mar 266:02 late1.91° N−18.3 s
Tue, Mar 27Minor Shortsol5:44 late2.31° N−18.3 s
Wed, Mar 285:26 late2.70° N−18.3 s
Thu, Mar 295:07 late3.09° N−18.3 s
Fri, Mar 304:49 late3.48° N−18.3 s
Sat, Mar 314:31 late3.87° N−18.2 s

April

DateSundialDeclinationSolar day
Sun, Apr 14:12 late4.25° N−18.1 s
Mon, Apr 23:54 late4.64° N−18.0 s
Tue, Apr 3Outward Midreach3:36 late5.02° N−17.9 s
Wed, Apr 43:18 late5.41° N−17.8 s
Thu, Apr 53:00 late5.79° N−17.6 s
Fri, Apr 62:43 late6.17° N−17.4 s
Sat, Apr 72:26 late6.55° N−17.2 s
Sun, Apr 82:08 late6.92° N−17.0 s
Mon, Apr 91:52 late7.30° N−16.8 s
Tue, Apr 101:35 late7.67° N−16.5 s
Wed, Apr 111:19 late8.04° N−16.3 s
Thu, Apr 121:02 late8.41° N−16.0 s
Fri, Apr 130:47 late8.77° N−15.7 s
Sat, Apr 14Northbound Echosun0:31 late9.14° N−15.3 s
Sun, Apr 150:16 late9.50° N−15.0 s
Mon, Apr 16Vernal Evensun0:01 late9.85° N−14.7 s
Tue, Apr 170:13 early10.21° N−14.3 s
Wed, Apr 180:27 early10.56° N−13.9 s
Thu, Apr 190:41 early10.91° N−13.5 s
Fri, Apr 200:54 early11.26° N−13.1 s
Sat, Apr 211:07 early11.60° N−12.7 s
Sun, Apr 221:19 early11.94° N−12.3 s
Mon, Apr 231:31 early12.28° N−11.8 s
Tue, Apr 241:43 early12.61° N−11.4 s
Wed, Apr 251:54 early12.94° N−10.9 s
Thu, Apr 262:05 early13.27° N−10.4 s
Fri, Apr 272:15 early13.59° N−9.9 s
Sat, Apr 282:25 early13.91° N−9.4 s
Sun, Apr 292:34 early14.23° N−8.9 s
Mon, Apr 302:43 early14.54° N−8.4 s

May

DateSundialDeclinationSolar day
Tue, May 12:51 early14.85° N−7.9 s
Wed, May 22:59 early15.15° N−7.3 s
Thu, May 33:06 early15.45° N−6.8 s
Fri, May 43:13 early15.74° N−6.3 s
Sat, May 53:19 early16.04° N−5.7 s
Sun, May 6May Cross-Quarter3:24 early16.32° N−5.1 s
Mon, May 73:29 early16.60° N−4.6 s
Tue, May 83:33 early16.88° N−4.0 s
Wed, May 93:37 early17.15° N−3.4 s
Thu, May 103:40 early17.42° N−2.9 s
Fri, May 113:43 early17.68° N−2.3 s
Sat, May 123:45 early17.94° N−1.7 s
Sun, May 133:46 early18.20° N−1.1 s
Mon, May 143:47 early18.44° N−0.6 s
Tue, May 15Lesser Earlysun3:47 early18.68° N0.0 s
Wed, May 163:47 early18.92° N+0.6 s
Thu, May 173:46 early19.16° N+1.1 s
Fri, May 183:44 early19.38° N+1.7 s
Sat, May 193:42 early19.60° N+2.3 s
Sun, May 203:39 early19.82° N+2.8 s
Mon, May 213:36 early20.03° N+3.4 s
Tue, May 223:33 early20.23° N+3.9 s
Wed, May 233:29 early20.43° N+4.4 s
Thu, May 243:24 early20.63° N+4.9 s
Fri, May 253:19 early20.81° N+5.5 s
Sat, May 263:13 early20.99° N+6.0 s
Sun, May 273:07 early21.17° N+6.4 s
Mon, May 283:00 early21.34° N+6.9 s
Tue, May 292:53 early21.50° N+7.4 s
Wed, May 302:46 early21.66° N+7.8 s
Thu, May 312:38 early21.81° N+8.3 s

June

DateSundialDeclinationSolar day
Fri, Jun 12:29 early21.95° N+8.7 s
Sat, Jun 22:21 early22.09° N+9.1 s
Sun, Jun 32:11 early22.22° N+9.5 s
Mon, Jun 42:02 early22.34° N+9.8 s
Tue, Jun 51:52 early22.46° N+10.2 s
Wed, Jun 61:42 early22.57° N+10.5 s
Thu, Jun 71:31 early22.68° N+10.8 s
Fri, Jun 81:20 early22.78° N+11.1 s
Sat, Jun 91:08 early22.87° N+11.4 s
Sun, Jun 100:57 early22.95° N+11.7 s
Mon, Jun 110:45 early23.03° N+11.9 s
Tue, Jun 120:33 early23.10° N+12.1 s
Wed, Jun 130:21 early23.17° N+12.3 s
Thu, Jun 140:08 early23.23° N+12.5 s
Fri, Jun 15Estival Evensun0:05 late23.28° N+12.6 s
Sat, Jun 160:17 late23.32° N+12.8 s
Sun, Jun 170:30 late23.36° N+12.8 s
Mon, Jun 180:43 late23.39° N+12.9 s
Tue, Jun 190:56 late23.41° N+13.0 s
Wed, Jun 201:09 late23.43° N+13.0 s
Thu, Jun 21Minor Longsol1:22 late23.44° N+13.0 s
Fri, Jun 22June Solstice1:35 late23.45° N+13.0 s
Sat, Jun 231:48 late23.44° N+12.9 s
Sun, Jun 242:01 late23.43° N+12.9 s
Mon, Jun 252:14 late23.41° N+12.8 s
Tue, Jun 262:27 late23.39° N+12.7 s
Wed, Jun 272:39 late23.36° N+12.6 s
Thu, Jun 282:51 late23.32° N+12.4 s
Fri, Jun 293:04 late23.28° N+12.2 s
Sat, Jun 303:16 late23.22° N+12.0 s

July

DateSundialDeclinationSolar day
Sun, Jul 13:27 late23.17° N+11.8 s
Mon, Jul 23:39 late23.10° N+11.5 s
Tue, Jul 33:50 late23.03° N+11.3 s
Wed, Jul 44:01 late22.95° N+11.0 s
Thu, Jul 54:12 late22.86° N+10.7 s
Fri, Jul 6Aphelion4:23 late22.77° N+10.3 s
Sat, Jul 74:33 late22.67° N+10.0 s
Sun, Jul 84:43 late22.57° N+9.6 s
Mon, Jul 94:52 late22.46° N+9.2 s
Tue, Jul 105:01 late22.34° N+8.8 s
Wed, Jul 115:10 late22.21° N+8.4 s
Thu, Jul 125:18 late22.08° N+8.0 s
Fri, Jul 135:26 late21.95° N+7.5 s
Sat, Jul 145:33 late21.80° N+7.0 s
Sun, Jul 155:40 late21.65° N+6.6 s
Mon, Jul 165:47 late21.50° N+6.1 s
Tue, Jul 175:53 late21.34° N+5.5 s
Wed, Jul 185:58 late21.17° N+5.0 s
Thu, Jul 196:03 late20.99° N+4.5 s
Fri, Jul 206:07 late20.81° N+4.0 s
Sat, Jul 216:11 late20.63° N+3.4 s
Sun, Jul 226:14 late20.44° N+2.8 s
Mon, Jul 236:16 late20.24° N+2.3 s
Tue, Jul 246:18 late20.04° N+1.7 s
Wed, Jul 256:20 late19.83° N+1.1 s
Thu, Jul 266:20 late19.61° N+0.5 s
Fri, Jul 27Lesser Latesun6:20 late19.40° N−0.1 s
Sat, Jul 286:20 late19.17° N−0.7 s
Sun, Jul 296:19 late18.94° N−1.3 s
Mon, Jul 306:17 late18.71° N−1.9 s
Tue, Jul 316:15 late18.47° N−2.5 s

August

DateSundialDeclinationSolar day
Wed, Aug 16:12 late18.22° N−3.1 s
Thu, Aug 26:09 late17.97° N−3.7 s
Fri, Aug 36:05 late17.71° N−4.3 s
Sat, Aug 46:00 late17.45° N−4.9 s
Sun, Aug 55:55 late17.19° N−5.5 s
Mon, Aug 65:49 late16.92° N−6.1 s
Tue, Aug 75:43 late16.65° N−6.7 s
Wed, Aug 8August Cross-Quarter5:36 late16.37° N−7.3 s
Thu, Aug 95:28 late16.09° N−7.9 s
Fri, Aug 105:20 late15.80° N−8.4 s
Sat, Aug 115:12 late15.51° N−9.0 s
Sun, Aug 125:02 late15.21° N−9.6 s
Mon, Aug 134:53 late14.91° N−10.1 s
Tue, Aug 144:42 late14.61° N−10.7 s
Wed, Aug 154:31 late14.30° N−11.2 s
Thu, Aug 164:20 late13.99° N−11.8 s
Fri, Aug 174:08 late13.68° N−12.3 s
Sat, Aug 183:56 late13.36° N−12.8 s
Sun, Aug 193:43 late13.03° N−13.3 s
Mon, Aug 203:29 late12.71° N−13.8 s
Tue, Aug 213:15 late12.38° N−14.3 s
Wed, Aug 223:00 late12.05° N−14.7 s
Thu, Aug 232:45 late11.71° N−15.2 s
Fri, Aug 242:30 late11.37° N−15.6 s
Sat, Aug 252:14 late11.03° N−16.1 s
Sun, Aug 261:57 late10.69° N−16.5 s
Mon, Aug 271:41 late10.34° N−16.9 s
Tue, Aug 281:24 late9.99° N−17.3 s
Wed, Aug 291:06 late9.64° N−17.6 s
Thu, Aug 300:48 late9.28° N−18.0 s
Fri, Aug 31Southbound Echosun0:30 late8.93° N−18.3 s

September

DateSundialDeclinationSolar day
Sat, Sep 10:12 late8.57° N−18.6 s
Sun, Sep 2Autumnal Evensun0:07 early8.21° N−18.9 s
Mon, Sep 30:26 early7.84° N−19.2 s
Tue, Sep 40:46 early7.47° N−19.5 s
Wed, Sep 51:05 early7.11° N−19.7 s
Thu, Sep 61:25 early6.74° N−19.9 s
Fri, Sep 71:45 early6.36° N−20.2 s
Sat, Sep 82:05 early5.99° N−20.4 s
Sun, Sep 92:26 early5.61° N−20.5 s
Mon, Sep 102:46 early5.24° N−20.7 s
Tue, Sep 113:07 early4.86° N−20.8 s
Wed, Sep 123:28 early4.48° N−21.0 s
Thu, Sep 133:49 early4.09° N−21.1 s
Fri, Sep 144:10 early3.71° N−21.1 s
Sat, Sep 154:31 early3.33° N−21.2 s
Sun, Sep 164:52 early2.94° N−21.2 s
Mon, Sep 175:13 early2.56° N−21.3 s
Tue, Sep 18Major Shortsol5:34 early2.17° N−21.3 s
Wed, Sep 195:56 early1.78° N−21.3 s
Thu, Sep 206:17 early1.40° N−21.2 s
Fri, Sep 216:38 early1.01° N−21.1 s
Sat, Sep 226:59 early0.62° N−21.1 s
Sun, Sep 237:21 early0.23° N−21.0 s
Mon, Sep 24September Equinox7:42 early0.16° S−20.9 s
Tue, Sep 258:02 early0.55° S−20.7 s
Wed, Sep 268:23 early0.94° S−20.6 s
Thu, Sep 278:44 early1.33° S−20.4 s
Fri, Sep 289:04 early1.72° S−20.2 s
Sat, Sep 299:24 early2.11° S−19.9 s
Sun, Sep 309:44 early2.50° S−19.7 s

October

DateSundialDeclinationSolar day
Mon, Oct 110:04 early2.89° S−19.4 s
Tue, Oct 210:23 early3.28° S−19.2 s
Wed, Oct 310:42 early3.66° S−18.9 s
Thu, Oct 4Inward Midreach11:01 early4.05° S−18.5 s
Fri, Oct 511:19 early4.44° S−18.2 s
Sat, Oct 611:37 early4.82° S−17.8 s
Sun, Oct 711:54 early5.21° S−17.4 s
Mon, Oct 812:12 early5.59° S−17.0 s
Tue, Oct 912:28 early5.97° S−16.6 s
Wed, Oct 1012:45 early6.36° S−16.2 s
Thu, Oct 1113:00 early6.73° S−15.7 s
Fri, Oct 1213:16 early7.11° S−15.2 s
Sat, Oct 1313:31 early7.49° S−14.7 s
Sun, Oct 1413:45 early7.86° S−14.2 s
Mon, Oct 1513:59 early8.24° S−13.7 s
Tue, Oct 1614:12 early8.61° S−13.1 s
Wed, Oct 1714:25 early8.98° S−12.5 s
Thu, Oct 1814:37 early9.34° S−11.9 s
Fri, Oct 1914:49 early9.71° S−11.3 s
Sat, Oct 2015:00 early10.07° S−10.7 s
Sun, Oct 2115:11 early10.43° S−10.1 s
Mon, Oct 2215:21 early10.79° S−9.4 s
Tue, Oct 2315:30 early11.14° S−8.8 s
Wed, Oct 2415:38 early11.49° S−8.1 s
Thu, Oct 2515:46 early11.84° S−7.4 s
Fri, Oct 2615:53 early12.19° S−6.6 s
Sat, Oct 2715:59 early12.53° S−5.9 s
Sun, Oct 2816:05 early12.87° S−5.2 s
Mon, Oct 2916:10 early13.20° S−4.4 s
Tue, Oct 3016:14 early13.54° S−3.7 s
Wed, Oct 3116:17 early13.87° S−2.9 s

November

DateSundialDeclinationSolar day
Thu, Nov 116:20 early14.19° S−2.1 s
Fri, Nov 216:21 early14.51° S−1.3 s
Sat, Nov 316:22 early14.83° S−0.5 s
Sun, Nov 4Great Earlysun16:22 early15.14° S+0.3 s
Mon, Nov 516:22 early15.45° S+1.1 s
Tue, Nov 616:20 early15.76° S+2.0 s
Wed, Nov 716:17 early16.06° S+2.8 s
Thu, Nov 8November Cross-Quarter16:14 early16.36° S+3.6 s
Fri, Nov 916:10 early16.65° S+4.5 s
Sat, Nov 1016:05 early16.94° S+5.3 s
Sun, Nov 1115:59 early17.22° S+6.2 s
Mon, Nov 1215:52 early17.50° S+7.0 s
Tue, Nov 1315:45 early17.77° S+7.9 s
Wed, Nov 1415:37 early18.04° S+8.7 s
Thu, Nov 1515:27 early18.30° S+9.6 s
Fri, Nov 1615:17 early18.55° S+10.4 s
Sat, Nov 1715:07 early18.81° S+11.3 s
Sun, Nov 1814:55 early19.05° S+12.1 s
Mon, Nov 1914:43 early19.29° S+12.9 s
Tue, Nov 2014:29 early19.53° S+13.8 s
Wed, Nov 2114:15 early19.75° S+14.6 s
Thu, Nov 2214:00 early19.98° S+15.4 s
Fri, Nov 2313:45 early20.19° S+16.2 s
Sat, Nov 2413:28 early20.40° S+16.9 s
Sun, Nov 2513:11 early20.61° S+17.7 s
Mon, Nov 2612:53 early20.80° S+18.5 s
Tue, Nov 2712:34 early21.00° S+19.2 s
Wed, Nov 2812:15 early21.18° S+19.9 s
Thu, Nov 2911:54 early21.36° S+20.6 s
Fri, Nov 3011:33 early21.53° S+21.3 s

December

DateSundialDeclinationSolar day
Sat, Dec 111:12 early21.69° S+22.0 s
Sun, Dec 210:49 early21.85° S+22.7 s
Mon, Dec 310:26 early22.00° S+23.3 s
Tue, Dec 410:03 early22.14° S+23.9 s
Wed, Dec 59:38 early22.28° S+24.5 s
Thu, Dec 69:13 early22.41° S+25.0 s
Fri, Dec 78:48 early22.53° S+25.6 s
Sat, Dec 88:22 early22.64° S+26.1 s
Sun, Dec 97:56 early22.75° S+26.5 s
Mon, Dec 107:29 early22.85° S+27.0 s
Tue, Dec 117:02 early22.94° S+27.4 s
Wed, Dec 126:34 early23.03° S+27.8 s
Thu, Dec 136:06 early23.10° S+28.2 s
Fri, Dec 145:38 early23.17° S+28.5 s
Sat, Dec 155:09 early23.23° S+28.8 s
Sun, Dec 164:40 early23.29° S+29.1 s
Mon, Dec 174:11 early23.33° S+29.3 s
Tue, Dec 183:42 early23.37° S+29.5 s
Wed, Dec 193:12 early23.40° S+29.6 s
Thu, Dec 202:42 early23.42° S+29.8 s
Fri, Dec 212:13 early23.44° S+29.9 s
Sat, Dec 22December Solstice1:43 early23.45° S+29.9 s
Sun, Dec 23Major Longsol1:13 early23.44° S+29.9 s
Mon, Dec 240:43 early23.43° S+29.9 s
Tue, Dec 25Hibernal Evensun0:13 early23.42° S+29.9 s
Wed, Dec 260:17 late23.39° S+29.8 s
Thu, Dec 270:46 late23.36° S+29.7 s
Fri, Dec 281:16 late23.32° S+29.6 s
Sat, Dec 291:45 late23.27° S+29.4 s
Sun, Dec 302:15 late23.22° S+29.2 s
Mon, Dec 312:44 late23.15° S+28.9 s

Reading the table

Sundial is the equation of time: minutes and seconds the Sun stands ahead of the clock (early) or behind it (late) at mean noon. To turn a sundial reading into mean time at your longitude, take an early Sun’s minutes off the reading and add a late Sun’s. Then add four minutes for every degree you are west of your time zone’s meridian (subtract east of it), and an hour in daylight saving time.

The equation of time changes by at most half a minute a day, so a value taken at 12:00 UT holds anywhere on Earth to within about fifteen seconds. Declination is the Sun’s angle north or south of the celestial equator. Solar day is the time from one solar noon to the next, minus 24 hours; its peaks are Major and MinorLongsol and Shortsol.

Values come from NASA JPL’s DE440 ephemeris, sampled daily and read at 12:00 UT, to within about 0.15 seconds of the equation of time. Moments are listed on their UTC date. See the methodology, or download every year’s moments from the data page.