Deep Dive on Time in Go & Distributed Databases
For an engineering breakdown of monotonic clocks in Go, monotonic vs wall clocks, time zone political shifts, and the right way to store timestamps across PostgreSQL, Couchbase, and mobile clients, read our guide: Just About Go Time.
How to Identify Timestamp Magnitudes
When dealing with distributed systems, databases, and message queues (Kafka, RabbitMQ, Redis), timestamps arrive in varying precisions:
| Precision | Digits | Example | Common Emitter |
|---|---|---|---|
| Seconds | 10 digits | 1715344800 | Unix date +%s, Postgres EXTRACT(EPOCH), standard HTTP headers |
| Milliseconds | 13 digits | 1715344800000 | JavaScript Date.now(), Java System.currentTimeMillis(), MongoDB ObjectID |
| Microseconds | 16 digits | 1715344800000000 | Python time.time_ns() // 1000, PostgreSQL timestamp internal storage |
| Nanoseconds | 19 digits | 1715344800000000000 | Go time.Now().UnixNano(), Linux high-res timers (CLOCK_REALTIME) |
Epoch Conversion Cheat Sheet
A quick reference for getting the current Unix timestamp and parsing an epoch integer (1800000000) into a human-readable date across common environments:
1. Programming Languages
| Language | Get Current Epoch (Seconds) | Convert Epoch to Date (1800000000) |
|---|---|---|
| Go | time.Now().Unix() | time.Unix(1800000000, 0) |
| Python | import time; time.time() | import time; time.ctime(1800000000) |
| JavaScript / Node | Math.floor(Date.now() / 1000) | new Date(1800000000 * 1000).toLocaleString() |
| Java | System.currentTimeMillis() / 1000 | java.time.Instant.ofEpochSecond(1800000000) |
| C# (.NET) | DateTimeOffset.UtcNow.ToUnixTimeSeconds() | DateTimeOffset.FromUnixTimeSeconds(1800000000).DateTime |
| C++ | std::chrono::system_clock::now().time_since_epoch() | auto t = std::chrono::system_clock::from_time_t(1800000000); |
| C | time(NULL) | ctime(&epoch) |
| Rust | SystemTime::now().duration_since(UNIX_EPOCH)?.as_secs() | DateTime::from_timestamp(1800000000, 0) |
| Ruby | Time.now.to_i | Time.at(1800000000) |
| PHP | time() | date(‘r’, 1800000000) |
| Dart | DateTime.now().millisecondsSinceEpoch ~/ 1000 | DateTime.fromMillisecondsSinceEpoch(1800000000 * 1000) |
| Lua | os.time() | os.date(’%c’, 1800000000) |
| R | as.numeric(Sys.time()) | as.POSIXct(1800000000, origin=“1970-01-01”, tz=“GMT”) |
2. Databases
| Database | Get Current Epoch (Seconds) | Convert Epoch to Timestamp (1800000000) |
|---|---|---|
| PostgreSQL | SELECT EXTRACT(EPOCH FROM now()); | SELECT TO_TIMESTAMP(1800000000); |
| MySQL / MariaDB | SELECT UNIX_TIMESTAMP(NOW()); | SELECT FROM_UNIXTIME(1800000000); |
| SQLite | SELECT unixepoch(); | SELECT datetime(1800000000, ‘unixepoch’); |
| SQL Server (T-SQL) | SELECT DATEDIFF(SECOND, ‘1970-01-01’, GETUTCDATE()); | SELECT DATEADD(SECOND, 1800000000, ‘1970-01-01’); |
3. Operating Systems & Shells
| Shell / OS | Get Current Epoch (Seconds) | Convert Epoch to Date (1800000000) |
|---|---|---|
| Linux / GNU Bash | date +%s | date -d @1800000000 (or date -ud @1800000000 for UTC) |
| macOS / BSD | date +%s | date -r 1800000000 (or date -u -r 1800000000 for UTC) |
| PowerShell | [DateTimeOffset]::Now.ToUnixTimeSeconds() | [DateTimeOffset]::FromUnixTimeSeconds(1800000000).LocalDateTime |
4. Spreadsheets
| Tool | Formula (Epoch in Cell A1) | Note |
|---|---|---|
| Excel / Sheets / Calc | =(A1 / 86400) + 25569 | Format cell as Date/Time (UTC). Add +(offset / 24) for local time zones. |
The Year 2038 Problem (Y2K38)
Systems storing Unix timestamps as a signed 32-bit integer (int32) will overflow on:
Tuesday, January 19, 2038 at 03:14:07 UTC
At that exact second, the value rolls over from 2,147,483,647 to -2,147,483,648, causing systems to interpret the date as December 13, 1901. Modern 64-bit systems (int64) extend this deadline by approximately 292 billion years.