Master PHP Time Functions: Get, Format, Calculate, and Set Timezones

In PHP development, handling dates and times is a common task, and PHP offers powerful functions to simplify these operations.

Getting the current time

Use time() to obtain the current Unix timestamp. Example:

$current_time = time();
echo $current_time;

Convert the timestamp to a readable format with date():

$current_time = time();
$date = date('Y-m-d H:i:s', $current_time);
echo $date;

Formatting dates and times

The date() function accepts format characters such as Y (year), m (month), d (day), H (hour), i (minute), and s (second). Example:

$current_time = time();
$date = date('Y-m-d H:i:s', $current_time);
echo $date;

Time calculations

Use strtotime() to parse human‑readable strings into timestamps. Adding one day:

$future_time = strtotime('+1 day');
$date = date('Y-m-d', $future_time);
echo $date;

Calculating the difference between two dates:

$start_date = strtotime('2021-11-01');
$end_date   = strtotime('2021-11-05');
$diff_days  = ($end_date - $start_date) / (60 * 60 * 24);
echo $diff_days;

Setting the timezone

Set the default timezone with date_default_timezone_set(). Example for Shanghai:

date_default_timezone_set('Asia/Shanghai');
$current_time = time();
$date = date('Y-m-d H:i:s', $current_time);
echo $date;

Conclusion

This guide covered the most common PHP time functions—including retrieving the current time, formatting dates, performing calculations, and configuring timezones—helping developers handle time‑related tasks efficiently.