Every Day Counts
Fermat Prime Days
 
Age: 18,868 days
Date of birth
Your 5th Fermat Prime Day is on
Saturday
when you will be
65,537 days old

Fermat Prime Days occur when your day age is a Fermat prime number.

Fermat primes are of the form 22n

As of 2011 these are the only known Fermat primes, and conjecturally the only Fermat primes.

We have yet to hear from someone who has held a Fermat Prime Day party.

Remind me, please


Next Prime Events
Day Age
Event
Days Ahead
Year Age
14 Dec 2025
18,869
tomorrow
51
07 May 2026
19,013
145
52
20 May 2027
19,391
523
53
20 May 2027
19,391
523
53
21 Jun 2027
19,423
555
53
09 Jul 2027
19,441
573
53
16 Nov 2028
19,937
1,069
54
29 Jan 2029
20,011
1,143
54
01 Oct 2052
28,657
9,789
78
27 Jan 2082
39,367
20,499
107
29 Dec 2093
43,721
24,853
119
29 May 2107
48,619
29,751
133
22 Sep 2153
65,537
46,669
179
05 Nov 2248
100,279
81,411
274
25 May 2272
108,881
90,013
298
25 Feb 2333
131,071
112,203
358
19 Jun 7791
2,124,679
2,105,811
5817
Ordinal
Day Age
Date
Age
1st
3
20 Apr 1974
0
2nd
5
22 Apr 1974
0
3rd
17
04 May 1974
0
4th
257
30 Dec 1974
0
5th
65,537
22 Sep 2153
179
1