How do I get a Unix timestamp in C?
Use time(NULL) from time.h for epoch seconds. It is portable and works well across Linux, macOS, and Windows C runtimes.
C Get Unix Timestamp in 2026
If you searched for c get unix timestamp, you likely need a reliable epoch value for API signatures, event logs, or scheduled tasks. In 2026, the simplest production pattern is still to generate epoch values directly in C as integers, then convert only for readable output during debugging.
Use 10-digit seconds for most backend payloads. Use 13-digit milliseconds when your client or queue explicitly requires higher precision. Keeping the unit consistent across services prevents hard-to-debug time drift and parsing issues.
Copy-ready C examples
Unix timestamp seconds
#include <time.h> time_t epoch_seconds = time(NULL);
Unix timestamp 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 a broader C walkthrough, see Unix timestamp in C. For an alternate query variant, open C get Unix time. To decode raw values from logs, use Unix timestamp to date.
Need an instant live value for validation? Check current timestamp now, or open the main epoch converter tool.
Related developer tool
If your C service runs on schedules, validate job syntax with Cron Expression Builder.
Frequently Asked Questions
How can I get milliseconds in C?
Use clock_gettime(CLOCK_REALTIME, &ts), then compute ts.tv_sec * 1000 + ts.tv_nsec / 1000000 and store it in a 64-bit integer.
Should C services store local time strings or epoch integers?
Store epoch integers in UTC. Convert to local display formats only at the UI layer to avoid timezone and daylight-saving issues.
Why does my converted date look wrong?
Most errors come from mixing units. A 10-digit value is seconds, while a 13-digit value is milliseconds. Confirm the unit before conversion.