How do I get Unix timestamp now in C?
Use time(NULL) from time.h for a current epoch value in seconds. It is the most portable default for C services and CLIs.
C Unix Timestamp Now in 2026
This page is for the query c unix timestamp when you specifically need a current value now for API signatures, event ordering, or retry windows. In 2026, the safest implementation is to generate the epoch value at write time, store it as a raw integer in UTC, and only convert to a human-readable date in dashboards or logs.
In C projects, seconds are usually enough for auth and cache expiry. Milliseconds are better for precise telemetry or queue timing. The critical rule is consistency: avoid mixing units in one table or endpoint. If an upstream service sends milliseconds while your C process expects seconds, normalize immediately before comparison.
Copy-ready C snippets
Current epoch seconds
#include <time.h> time_t epoch_seconds = time(NULL);
Current epoch milliseconds
#include <time.h> struct timespec ts; clock_gettime(CLOCK_REALTIME, &ts); long long epoch_ms = (long long)ts.tv_sec * 1000LL + ts.tv_nsec / 1000000LL;
Related EpochConverter pages
For language-specific notes, visit Unix timestamp in C. If you need millisecond details, use C get Unix timestamp milliseconds. To decode output while debugging, open Unix timestamp to date.
Need a live reference value first? Check current timestamp now. Or use the main epoch converter tool.
Related developer tool
If this code runs on scheduled jobs, validate interval syntax with Cron Expression Builder.
Frequently Asked Questions
How do I get current Unix milliseconds in C?
Use clock_gettime(CLOCK_REALTIME, &ts), then compute ts.tv_sec * 1000 + ts.tv_nsec / 1000000 and store the result in a 64-bit integer.
Why are my timestamps off by hours?
Epoch integers are timezone-neutral. Offsets usually happen when formatting for display or when local time is mixed into storage logic.
Should I store seconds or milliseconds in 2026?
Store whichever unit your API contract expects, but document it clearly. Ten digits typically means seconds and thirteen digits typically means milliseconds.