Cal Henderson, born on January 17, 1981, is a British computer programmer and author based in San Francisco. He is best known as the co-founder and CTO of Slack and for his role in developing the online community B3ta and the photo-sharing application Flickr. Henderson authored 'Building Scalable Web Sites' and has worked on various web projects, contributing to making technology more accessible. He is also active in open-source software and has engaged in political donations, demonstrating his wide-ranging influence in technology and community engagement.
Zodiac Sign (Western)
Sunsign, Tropical Zodiac
Zodiac Sign (Vedic)
Moonsign, Sidereal Zodiac
Age (Today)
Your next birthday is 348 days away.
Place of Birth
Time Zone -
Chinese Zodiac Sign
Birth Number
Life Path Number
Name Number (Chaldean)
Name Number (Pythagorean)
Meaning of the name - Cal
While Cal doesn't have a direct meaning, it is often associated with warmth, friendliness, and a vibrant spirit. It can also evoke a sense of simplicity and strength.
Read Full Cal Name AnalysisJanuary 17, 1981 Facts
Generation Group
Cal Henderson belongs to the Millennials group.
Educated At: Sharnbrook Academy
Occupation: blogger | engineer
Employers: Slack | B3ta | Ludicorp | Yahoo | EMAP | Tiny Speck
Astrology Analysis
Ephemeris for January 17, 1981
Note: Moon position is location and time sensitive.| Planet | Position (Tropical, Western) | Transits on January 17, 2025 | Secondary Progressions for January 17, 2025 |
|---|---|---|---|
| Sun | 27 Capricorn 31 | 27 Capricorn 50 | 12 Pisces 2 |
| Moon | 24 Gemini 9 | 12 Virgo 30 | 23 Capricorn 58 |
| Mercury | 8 Aquarius 30 | 13 Capricorn 40 | 19 Aquarius 51 |
| Venus | 8 Capricorn 2 | 14 Pisces 48 | 3 Pisces 4 |
| Mars | 14 Aquarius 0 | 25 Cancer 34 | 18 Pisces 45 |
| Jupiter | 10 Libra 9 | 11 Gemini 48 | 8 Libra 9 |
| Saturn | 10 Libra 11 | 15 Pisces 54 | 8 Libra 40 |
| Uranus | 29 Scorpio 13 | 23 Taurus 21 | 0 Sagittarius 10 |
| Neptune | 23 Sagittarius 39 | 27 Pisces 36 | 24 Sagittarius 42 |
| Pluto | 24 Libra 19 | 1 Aquarius 35 | 23 Libra 59 |
| Rahu | 11 Leo 37 | 0 Aries 36 | 9 Leo 18 |
| Ketu | 11 Aquarius 37 | 0 Libra 36 | 9 Aquarius 18 |
Chandra Kundali (Equal House, North Indian Diamond Chart)
Astrology Transits Analysis for Year 2025
Note: Multiple transits occurring in close proximity often signify a major event in a person's life.Cal Henderson's 2025 Transits to Natal Planets
- Mars opposition Sun
Exact: 11 January, 2025 - Jupiter trine Ketu
Exact: 11 January, 2025 - Jupiter trine Jupiter
Exact: 31 January, 2025 - Jupiter trine Saturn
Exact: 31 January, 2025 - Jupiter trine Mars
Exact: 22 March, 2025 - Mars opposition Sun
Exact: 11 April, 2025 - Jupiter conjunction Moon
Exact: 11 May, 2025 - Jupiter opposition Venus
Exact: 20 July, 2025 - Mars square Venus
Exact: 19 August, 2025 - Mars square Sun
Exact: 18 September, 2025 - Mars square Ketu
Exact: 08 October, 2025 - Mars aspects Moon
Exact: 28 October, 2025 - Mars opposition Moon
Exact: 07 December, 2025
