Current Time with ard/chrono

The ard/chrono module provides access to the current Unix timestamp (seconds since 1970-01-01 UTC).

The chrono module provides:

• Current time as integer timestamp for database operations and calculations

use ard/chrono

fn main() {
  let now = chrono::now()
  io::print("Current Unix timestamp: {now}")
}

API

fn now() Int

Get the current Unix timestamp in seconds.

Returns an integer representing seconds since 1970-01-01 UTC.

use ard/chrono

let now = chrono::now()
io::print("Current timestamp: {now}")

Examples

Cache TTL Calculation

use ard/chrono
use ard/sql

fn cache_set(db: sql::Database, key: Str, value: Dynamic, ttl_seconds: Int) {
  let now = chrono::now()
  let expires_at = now + ttl_seconds
  db.query("INSERT INTO cache (key, value, expires_at) VALUES (?, ?, ?)")
    .run([key, json::encode(value), expires_at])
}

Cache Expiration Check

use ard/chrono

fn is_expired(expires_at: Int) Bool {
  let now = chrono::now()
  expires_at <= now
}

Timestamp Comparison

use ard/chrono

let now = chrono::now()
let one_hour_ago = now - 3600
let one_hour_later = now + 3600

io::print("Past: {one_hour_ago}")
io::print("Now: {now}")
io::print("Future: {one_hour_later}")

Use Cases

• Cache TTL Management - Calculate expiration times and check if cached data is stale
• Database Timestamps - Store current time in INTEGER columns
• Rate Limiting - Track request windows by timestamp
• Event Logging - Record when events occurred
• Time Comparisons - Check if deadlines have passed

Return Type

chrono::now() returns an Int - the Unix timestamp in seconds.

use ard/chrono

let now = chrono::now()
// now is an integer, use it directly
let future = now + 3600

Precision

• Returns seconds (integer) since Unix epoch (1970-01-01 UTC)
• No fractional seconds or nanoseconds
• Sufficient for cache TTLs, rate limiting, and most timestamp needs

Timezone

• Always returns UTC (Unix timestamps are timezone-agnostic)
• For human-readable local time with timezone, use ard/dates

Integration with Other Modules

With ard/duration for future timestamps

use ard/chrono
use ard/duration

let now = chrono::now()
// Add 1 hour (duration returns nanoseconds, divide to get seconds)
let in_one_hour = now + duration::from_hours(1) / 1000000000

With ard/dates for human-readable output

use ard/chrono
use ard/dates

let human_date = dates::get_today()  // "2025-01-17"
let now = chrono::now()
io::print("{human_date} [{now}]")

Error Handling

chrono::now() returns an Int directly—no error handling needed. System clock failures are extremely rare and not worth defensive programming.