The following table shows every day of the year, from Jan. 1 to Dec. 31, along with a ranking based on how many babies were born in the United States on that date between 1973 and 1999. Jan. 1, for example, was the 364th most popular birthday for a baby during those years; only Dec. 25 and Feb. 29 were less popular. Sept. 16 was the most popular birthday.
| Rank | Month | Day |
| 364 | 1 | 1 |
| 362 | 1 | 2 |
| 356 | 1 | 3 |
| 350 | 1 | 4 |
| 338 | 1 | 5 |
| 301 | 1 | 6 |
| 324 | 1 | 7 |
| 347 | 1 | 8 |
| 351 | 1 | 9 |
| 349 | 1 | 10 |
| 341 | 1 | 11 |
| 306 | 1 | 12 |
| 316 | 1 | 13 |
| 260 | 1 | 14 |
| 304 | 1 | 15 |
| 322 | 1 | 16 |
| 337 | 1 | 17 |
| 317 | 1 | 18 |
| 302 | 1 | 19 |
| 240 | 1 | 20 |
| 279 | 1 | 21 |
| 271 | 1 | 22 |
| 294 | 1 | 23 |
| 333 | 1 | 24 |
| 299 | 1 | 25 |
| 298 | 1 | 26 |
| 262 | 1 | 27 |
| 280 | 1 | 28 |
| 285 | 1 | 29 |
| 314 | 1 | 30 |
| 343 | 1 | 31 |
| 330 | 2 | 1 |
| 253 | 2 | 2 |
| 256 | 2 | 3 |
| 281 | 2 | 4 |
| 287 | 2 | 5 |
| 293 | 2 | 6 |
| 332 | 2 | 7 |
| 308 | 2 | 8 |
| 245 | 2 | 9 |
| 171 | 2 | 10 |
| 214 | 2 | 11 |
| 166 | 2 | 12 |
| 331 | 2 | 13 |
| 103 | 2 | 14 |
| 248 | 2 | 15 |
| 244 | 2 | 16 |
| 232 | 2 | 17 |
| 237 | 2 | 18 |
| 246 | 2 | 19 |
| 206 | 2 | 20 |
| 292 | 2 | 21 |
| 218 | 2 | 22 |
| 213 | 2 | 23 |
| 157 | 2 | 24 |
| 204 | 2 | 25 |
| 203 | 2 | 26 |
| 247 | 2 | 27 |
| 250 | 2 | 28 |
| 366 | 2 | 29 |
| 235 | 3 | 1 |
| 189 | 3 | 2 |
| 133 | 3 | 3 |
| 150 | 3 | 4 |
| 156 | 3 | 5 |
| 228 | 3 | 6 |
| 290 | 3 | 7 |
| 265 | 3 | 8 |
| 268 | 3 | 9 |
| 195 | 3 | 10 |
| 163 | 3 | 11 |
| 165 | 3 | 12 |
| 334 | 3 | 13 |
| 300 | 3 | 14 |
| 264 | 3 | 15 |
| 208 | 3 | 16 |
| 134 | 3 | 17 |
| 152 | 3 | 18 |
| 198 | 3 | 19 |
| 202 | 3 | 20 |
| 254 | 3 | 21 |
| 261 | 3 | 22 |
| 255 | 3 | 23 |
| 210 | 3 | 24 |
| 162 | 3 | 25 |
| 187 | 3 | 26 |
| 225 | 3 | 27 |
| 297 | 3 | 28 |
| 275 | 3 | 29 |
| 267 | 3 | 30 |
| 227 | 3 | 31 |
| 348 | 4 | 1 |
| 193 | 4 | 2 |
| 278 | 4 | 3 |
| 277 | 4 | 4 |
| 336 | 4 | 5 |
| 286 | 4 | 6 |
| 226 | 4 | 7 |
| 196 | 4 | 8 |
| 274 | 4 | 9 |
| 296 | 4 | 10 |
| 335 | 4 | 11 |
| 315 | 4 | 12 |
| 346 | 4 | 13 |
| 257 | 4 | 14 |
| 223 | 4 | 15 |
| 243 | 4 | 16 |
| 309 | 4 | 17 |
| 323 | 4 | 18 |
| 339 | 4 | 19 |
| 310 | 4 | 20 |
| 259 | 4 | 21 |
| 201 | 4 | 22 |
| 230 | 4 | 23 |
| 307 | 4 | 24 |
| 325 | 4 | 25 |
| 327 | 4 | 26 |
| 313 | 4 | 27 |
| 270 | 4 | 28 |
| 282 | 4 | 29 |
| 288 | 4 | 30 |
| 242 | 5 | 1 |
| 305 | 5 | 2 |
| 329 | 5 | 3 |
| 291 | 5 | 4 |
| 177 | 5 | 5 |
| 181 | 5 | 6 |
| 229 | 5 | 7 |
| 276 | 5 | 8 |
| 326 | 5 | 9 |
| 273 | 5 | 10 |
| 251 | 5 | 11 |
| 175 | 5 | 12 |
| 249 | 5 | 13 |
| 174 | 5 | 14 |
| 183 | 5 | 15 |
| 272 | 5 | 16 |
| 258 | 5 | 17 |
| 188 | 5 | 18 |
| 168 | 5 | 19 |
| 123 | 5 | 20 |
| 138 | 5 | 21 |
| 141 | 5 | 22 |
| 176 | 5 | 23 |
| 167 | 5 | 24 |
| 311 | 5 | 25 |
| 289 | 5 | 26 |
| 211 | 5 | 27 |
| 200 | 5 | 28 |
| 234 | 5 | 29 |
| 328 | 5 | 30 |
| 319 | 5 | 31 |
| 153 | 6 | 1 |
| 121 | 6 | 2 |
| 124 | 6 | 3 |
| 146 | 6 | 4 |
| 179 | 6 | 5 |
| 197 | 6 | 6 |
| 215 | 6 | 7 |
| 191 | 6 | 8 |
| 154 | 6 | 9 |
| 120 | 6 | 10 |
| 137 | 6 | 11 |
| 170 | 6 | 12 |
| 303 | 6 | 13 |
| 169 | 6 | 14 |
| 139 | 6 | 15 |
| 117 | 6 | 16 |
| 107 | 6 | 17 |
| 126 | 6 | 18 |
| 140 | 6 | 19 |
| 132 | 6 | 20 |
| 145 | 6 | 21 |
| 118 | 6 | 22 |
| 110 | 6 | 23 |
| 95 | 6 | 24 |
| 100 | 6 | 25 |
| 112 | 6 | 26 |
| 129 | 6 | 27 |
| 108 | 6 | 28 |
| 101 | 6 | 29 |
| 75 | 6 | 30 |
| 50 | 7 | 1 |
| 47 | 7 | 2 |
| 127 | 7 | 3 |
| 361 | 7 | 4 |
| 321 | 7 | 5 |
| 76 | 7 | 6 |
| 14 | 7 | 7 |
| 12 | 7 | 8 |
| 37 | 7 | 9 |
| 49 | 7 | 10 |
| 90 | 7 | 11 |
| 93 | 7 | 12 |
| 99 | 7 | 13 |
| 43 | 7 | 14 |
| 25 | 7 | 15 |
| 40 | 7 | 16 |
| 61 | 7 | 17 |
| 91 | 7 | 18 |
| 87 | 7 | 19 |
| 51 | 7 | 20 |
| 45 | 7 | 21 |
| 18 | 7 | 22 |
| 32 | 7 | 23 |
| 72 | 7 | 24 |
| 78 | 7 | 25 |
| 80 | 7 | 26 |
| 58 | 7 | 27 |
| 35 | 7 | 28 |
| 28 | 7 | 29 |
| 39 | 7 | 30 |
| 68 | 7 | 31 |
| 86 | 8 | 1 |
| 85 | 8 | 2 |
| 66 | 8 | 3 |
| 48 | 8 | 4 |
| 36 | 8 | 5 |
| 46 | 8 | 6 |
| 60 | 8 | 7 |
| 64 | 8 | 8 |
| 77 | 8 | 9 |
| 52 | 8 | 10 |
| 56 | 8 | 11 |
| 17 | 8 | 12 |
| 67 | 8 | 13 |
| 55 | 8 | 14 |
| 71 | 8 | 15 |
| 70 | 8 | 16 |
| 54 | 8 | 17 |
| 33 | 8 | 18 |
| 30 | 8 | 19 |
| 31 | 8 | 20 |
| 57 | 8 | 21 |
| 82 | 8 | 22 |
| 81 | 8 | 23 |
| 63 | 8 | 24 |
| 59 | 8 | 25 |
| 38 | 8 | 26 |
| 34 | 8 | 27 |
| 44 | 8 | 28 |
| 74 | 8 | 29 |
| 73 | 8 | 30 |
| 65 | 8 | 31 |
| 106 | 9 | 1 |
| 114 | 9 | 2 |
| 92 | 9 | 3 |
| 98 | 9 | 4 |
| 125 | 9 | 5 |
| 111 | 9 | 6 |
| 105 | 9 | 7 |
| 29 | 9 | 8 |
| 2 | 9 | 9 |
| 9 | 9 | 10 |
| 24 | 9 | 11 |
| 41 | 9 | 12 |
| 69 | 9 | 13 |
| 16 | 9 | 14 |
| 8 | 9 | 15 |
| 1 | 9 | 16 |
| 4 | 9 | 17 |
| 10 | 9 | 18 |
| 13 | 9 | 19 |
| 15 | 9 | 20 |
| 7 | 9 | 21 |
| 5 | 9 | 22 |
| 3 | 9 | 23 |
| 6 | 9 | 24 |
| 11 | 9 | 25 |
| 27 | 9 | 26 |
| 21 | 9 | 27 |
| 23 | 9 | 28 |
| 22 | 9 | 29 |
| 19 | 9 | 30 |
| 20 | 10 | 1 |
| 53 | 10 | 2 |
| 88 | 10 | 3 |
| 89 | 10 | 4 |
| 79 | 10 | 5 |
| 83 | 10 | 6 |
| 84 | 10 | 7 |
| 97 | 10 | 8 |
| 119 | 10 | 9 |
| 122 | 10 | 10 |
| 160 | 10 | 11 |
| 136 | 10 | 12 |
| 180 | 10 | 13 |
| 116 | 10 | 14 |
| 109 | 10 | 15 |
| 155 | 10 | 16 |
| 216 | 10 | 17 |
| 239 | 10 | 18 |
| 219 | 10 | 19 |
| 159 | 10 | 20 |
| 135 | 10 | 21 |
| 164 | 10 | 22 |
| 212 | 10 | 23 |
| 269 | 10 | 24 |
| 209 | 10 | 25 |
| 184 | 10 | 26 |
| 172 | 10 | 27 |
| 142 | 10 | 28 |
| 173 | 10 | 29 |
| 252 | 10 | 30 |
| 355 | 10 | 31 |
| 233 | 11 | 1 |
| 222 | 11 | 2 |
| 178 | 11 | 3 |
| 131 | 11 | 4 |
| 143 | 11 | 5 |
| 207 | 11 | 6 |
| 236 | 11 | 7 |
| 241 | 11 | 8 |
| 192 | 11 | 9 |
| 182 | 11 | 10 |
| 158 | 11 | 11 |
| 194 | 11 | 12 |
| 312 | 11 | 13 |
| 263 | 11 | 14 |
| 238 | 11 | 15 |
| 190 | 11 | 16 |
| 161 | 11 | 17 |
| 148 | 11 | 18 |
| 147 | 11 | 19 |
| 151 | 11 | 20 |
| 199 | 11 | 21 |
| 340 | 11 | 22 |
| 344 | 11 | 23 |
| 352 | 11 | 24 |
| 353 | 11 | 25 |
| 357 | 11 | 26 |
| 358 | 11 | 27 |
| 359 | 11 | 28 |
| 345 | 11 | 29 |
| 231 | 11 | 30 |
| 149 | 12 | 1 |
| 144 | 12 | 2 |
| 186 | 12 | 3 |
| 283 | 12 | 4 |
| 320 | 12 | 5 |
| 318 | 12 | 6 |
| 284 | 12 | 7 |
| 221 | 12 | 8 |
| 217 | 12 | 9 |
| 205 | 12 | 10 |
| 295 | 12 | 11 |
| 266 | 12 | 12 |
| 342 | 12 | 13 |
| 185 | 12 | 14 |
| 128 | 12 | 15 |
| 102 | 12 | 16 |
| 94 | 12 | 17 |
| 96 | 12 | 18 |
| 113 | 12 | 19 |
| 104 | 12 | 20 |
| 115 | 12 | 21 |
| 224 | 12 | 22 |
| 354 | 12 | 23 |
| 363 | 12 | 24 |
| 365 | 12 | 25 |
| 360 | 12 | 26 |
| 130 | 12 | 27 |
| 62 | 12 | 28 |
| 42 | 12 | 29 |
| 26 | 12 | 30 |
| 220 | 12 | 31 |
Source: Amitabh Chandra, Harvard University