How do I get the current Unix timestamp in C?
Use time(NULL) from time.h to get epoch seconds as time_t. It is portable and works on virtually every Unix-like and Windows C runtime.
C Get Unix Time in 2026
If you searched for c get unix time, you usually need either a stable 10-digit value for APIs or a 13-digit value for event logs. In 2026, the safest rule is still simple: use time(NULL) for seconds and clock_gettime when you need millisecond precision. Keep both values as integers so your C service can pass timestamps cleanly to JavaScript, Go, and SQL systems.
Unix timestamps are UTC-based. That means the raw number itself is timezone neutral. Store it as-is, then convert to local time only for UI output. Most cross-service bugs happen when teams mix local wall-clock strings with epoch integers.
Copy-ready C snippets
Current Unix seconds (portable)
#include <time.h> time_t epoch_seconds = time(NULL);
Current Unix 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;
Epoch seconds to UTC string
#include <time.h> char buf[32]; time_t ts = 1700000000; strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S UTC", gmtime(&ts));
Related EpochConverter pages
For a broader C walkthrough, see Unix timestamp in C. To compare your runtime output with live values, use current timestamp now. If you need readable output from a log value, open Unix timestamp to date. For unit debugging, use epoch seconds to milliseconds.
Need instant conversion while testing? Open the main epoch converter tool.
Related developer tool
If your C job runs on a schedule, validate cron syntax with Cron Expression Builder before deployment.
Frequently Asked Questions
How do I get Unix milliseconds in C?
Use clock_gettime(CLOCK_REALTIME, &ts), then compute ts.tv_sec * 1000 + ts.tv_nsec / 1000000. Keep the result in a 64-bit integer.
Should I store C timestamps as local time?
No. Store raw Unix epoch integers in UTC and format to local time only when displaying to users. This avoids timezone and daylight-saving bugs.
How can I convert epoch seconds back to a date in C?
Use gmtime or localtime with strftime for formatting. gmtime is best for system logs and APIs because it stays in UTC.