Hiring process8 levels
  1. 1 IQ Test
  2. 2 Additional Online Test (If Required)
  3. 3 Office Interview with Hiring Manager
  4. 4 Unpaid Test Task (Motivation Check)
  5. 5 Paid Test Task and Follow-Up Interview
  6. 6 Iterative Paid Test Tasks
  7. 7 Office Verification
  8. 8 Final Interview with the Founder

Problems > What Day Was It > Editorial

What Day Was It — Solution & Editorial

Back to the Problem

Zeller's congruence (shift Jan/Feb to months 13/14 of the previous year), or count days from a known anchor date.

Complexity: O(1)

Watch out: January and February must be treated as months 13 and 14 of the PREVIOUS year in Zeller's formula.