There’s an urban myth that claims that a month with five Fridays, five Saturdays, and five Sundays will only occur once in every 823 years.

This is, of course, stupid, as a moment of consideration will lay bare. But, for the sake of argument, let’s find out how often this "special" month occurs within the next 823 years.


2017: December
2019: March
2020: May
2021: January, October
2022: July
2023: December
2024: March
2025: August
2026: May
2027: January, October
2028: December
2030: March
2031: August
2032: October
2033: July
2034: December
2036: August
2037: May
2038: January, October
2039: July
2041: March
2042: August
2043: May
2044: January, July
2045: December
2047: March
2048: May
2049: January, October
2050: July
2051: December
2052: March
2053: August
2054: May
2055: January, October
2056: December
2058: March
2059: August
2060: October
2061: July
2062: December
2064: August
2065: May
2066: January, October
2067: July
2069: March
2070: August
2071: May
2072: January, July
2073: December
2075: March
2076: May
2077: January, October
2078: July
2079: December
2080: March
2081: August
2082: May
2083: January, October
2084: December
2086: March
2087: August
2088: October
2089: July
2090: December
2092: August
2093: May
2094: January, October
2095: July
2097: March
2098: August
2099: May
2100: January, October
2101: July
2102: December
2104: August
2105: May
2106: January, October
2107: July
2109: March
2110: August
2111: May
2112: January, July
2113: December
2115: March
2116: May
2117: January, October
2118: July
2119: December
2120: March
2121: August
2122: May
2123: January, October
2124: December
2126: March
2127: August
2128: October
2129: July
2130: December
2132: August
2133: May
2134: January, October
2135: July
2137: March
2138: August
2139: May
2140: January, July
2141: December
2143: March
2144: May
2145: January, October
2146: July
2147: December
2148: March
2149: August
2150: May
2151: January, October
2152: December
2154: March
2155: August
2156: October
2157: July
2158: December
2160: August
2161: May
2162: January, October
2163: July
2165: March
2166: August
2167: May
2168: January, July
2169: December
2171: March
2172: May
2173: January, October
2174: July
2175: December
2176: March
2177: August
2178: May
2179: January, October
2180: December
2182: March
2183: August
2184: October
2185: July
2186: December
2188: August
2189: May
2190: January, October
2191: July
2193: March
2194: August
2195: May
2196: January, July
2197: December
2199: March
2200: August
2201: May
2202: January, October
2203: July
2205: March
2206: August
2207: May
2208: January, July
2209: December
2211: March
2212: May
2213: January, October
2214: July
2215: December
2216: March
2217: August
2218: May
2219: January, October
2220: December
2222: March
2223: August
2224: October
2225: July
2226: December
2228: August
2229: May
2230: January, October
2231: July
2233: March
2234: August
2235: May
2236: January, July
2237: December
2239: March
2240: May
2241: January, October
2242: July
2243: December
2244: March
2245: August
2246: May
2247: January, October
2248: December
2250: March
2251: August
2252: October
2253: July
2254: December
2256: August
2257: May
2258: January, October
2259: July
2261: March
2262: August
2263: May
2264: January, July
2265: December
2267: March
2268: May
2269: January, October
2270: July
2271: December
2272: March
2273: August
2274: May
2275: January, October
2276: December
2278: March
2279: August
2280: October
2281: July
2282: December
2284: August
2285: May
2286: January, October
2287: July
2289: March
2290: August
2291: May
2292: January, July
2293: December
2295: March
2296: May
2297: January, October
2298: July
2299: December
2301: March
2302: August
2303: May
2304: January, July
2305: December
2307: March
2308: May
2309: January, October
2310: July
2311: December
2312: March
2313: August
2314: May
2315: January, October
2316: December
2318: March
2319: August
2320: October
2321: July
2322: December
2324: August
2325: May
2326: January, October
2327: July
2329: March
2330: August
2331: May
2332: January, July
2333: December
2335: March
2336: May
2337: January, October
2338: July
2339: December
2340: March
2341: August
2342: May
2343: January, October
2344: December
2346: March
2347: August
2348: October
2349: July
2350: December
2352: August
2353: May
2354: January, October
2355: July
2357: March
2358: August
2359: May
2360: January, July
2361: December
2363: March
2364: May
2365: January, October
2366: July
2367: December
2368: March
2369: August
2370: May
2371: January, October
2372: December
2374: March
2375: August
2376: October
2377: July
2378: December
2380: August
2381: May
2382: January, October
2383: July
2385: March
2386: August
2387: May
2388: January, July
2389: December
2391: March
2392: May
2393: January, October
2394: July
2395: December
2396: March
2397: August
2398: May
2399: January, October
2400: December
2402: March
2403: August
2404: October
2405: July
2406: December
2408: August
2409: May
2410: January, October
2411: July
2413: March
2414: August
2415: May
2416: January, July
2417: December
2419: March
2420: May
2421: January, October
2422: July
2423: December
2424: March
2425: August
2426: May
2427: January, October
2428: December
2430: March
2431: August
2432: October
2433: July
2434: December
2436: August
2437: May
2438: January, October
2439: July
2441: March
2442: August
2443: May
2444: January, July
2445: December
2447: March
2448: May
2449: January, October
2450: July
2451: December
2452: March
2453: August
2454: May
2455: January, October
2456: December
2458: March
2459: August
2460: October
2461: July
2462: December
2464: August
2465: May
2466: January, October
2467: July
2469: March
2470: August
2471: May
2472: January, July
2473: December
2475: March
2476: May
2477: January, October
2478: July
2479: December
2480: March
2481: August
2482: May
2483: January, October
2484: December
2486: March
2487: August
2488: October
2489: July
2490: December
2492: August
2493: May
2494: January, October
2495: July
2497: March
2498: August
2499: May
2500: January, October
2501: July
2502: December
2504: August
2505: May
2506: January, October
2507: July
2509: March
2510: August
2511: May
2512: January, July
2513: December
2515: March
2516: May
2517: January, October
2518: July
2519: December
2520: March
2521: August
2522: May
2523: January, October
2524: December
2526: March
2527: August
2528: October
2529: July
2530: December
2532: August
2533: May
2534: January, October
2535: July
2537: March
2538: August
2539: May
2540: January, July
2541: December
2543: March
2544: May
2545: January, October
2546: July
2547: December
2548: March
2549: August
2550: May
2551: January, October
2552: December
2554: March
2555: August
2556: October
2557: July
2558: December
2560: August
2561: May
2562: January, October
2563: July
2565: March
2566: August
2567: May
2568: January, July
2569: December
2571: March
2572: May
2573: January, October
2574: July
2575: December
2576: March
2577: August
2578: May
2579: January, October
2580: December
2582: March
2583: August
2584: October
2585: July
2586: December
2588: August
2589: May
2590: January, October
2591: July
2593: March
2594: August
2595: May
2596: January, July
2597: December
2599: March
2600: August
2601: May
2602: January, October
2603: July
2605: March
2606: August
2607: May
2608: January, July
2609: December
2611: March
2612: May
2613: January, October
2614: July
2615: December
2616: March
2617: August
2618: May
2619: January, October
2620: December
2622: March
2623: August
2624: October
2625: July
2626: December
2628: August
2629: May
2630: January, October
2631: July
2633: March
2634: August
2635: May
2636: January, July
2637: December
2639: March
2640: May
2641: January, October
2642: July
2643: December
2644: March
2645: August
2646: May
2647: January, October
2648: December
2650: March
2651: August
2652: October
2653: July
2654: December
2656: August
2657: May
2658: January, October
2659: July
2661: March
2662: August
2663: May
2664: January, July
2665: December
2667: March
2668: May
2669: January, October
2670: July
2671: December
2672: March
2673: August
2674: May
2675: January, October
2676: December
2678: March
2679: August
2680: October
2681: July
2682: December
2684: August
2685: May
2686: January, October
2687: July
2689: March
2690: August
2691: May
2692: January, July
2693: December
2695: March
2696: May
2697: January, October
2698: July
2699: December
2701: March
2702: August
2703: May
2704: January, July
2705: December
2707: March
2708: May
2709: January, October
2710: July
2711: December
2712: March
2713: August
2714: May
2715: January, October
2716: December
2718: March
2719: August
2720: October
2721: July
2722: December
2724: August
2725: May
2726: January, October
2727: July
2729: March
2730: August
2731: May
2732: January, July
2733: December
2735: March
2736: May
2737: January, October
2738: July
2739: December
2740: March
2741: August
2742: May
2743: January, October
2744: December
2746: March
2747: August
2748: October
2749: July
2750: December
2752: August
2753: May
2754: January, October
2755: July
2757: March
2758: August
2759: May
2760: January, July
2761: December
2763: March
2764: May
2765: January, October
2766: July
2767: December
2768: March
2769: August
2770: May
2771: January, October
2772: December
2774: March
2775: August
2776: October
2777: July
2778: December
2780: August
2781: May
2782: January, October
2783: July
2785: March
2786: August
2787: May
2788: January, July
2789: December
2791: March
2792: May
2793: January, October
2794: July
2795: December
2796: March
2797: August
2798: May
2799: January, October
2800: December
2802: March
2803: August
2804: October
2805: July
2806: December
2808: August
2809: May
2810: January, October
2811: July
2813: March
2814: August
2815: May
2816: January, July
2817: December
2819: March
2820: May
2821: January, October
2822: July
2823: December
2824: March
2825: August
2826: May
2827: January, October
2828: December
2830: March
2831: August
2832: October
2833: July
2834: December
2836: August
2837: May
2838: January, October
2839: July

This very special month will occur 823 times within the next 823 years which is in line with my prophecy.

Distribution:  
MonthactualexpectedDeviation
January119117,57141,22%
March117117,57140,49%
May119117,57141,22%
July119117,57141,22%
August117117,57140,49%
October116117,57141,34%
December116117,57141,34%
Average117,5714117,57141,04%

1607