PHP strtotime() Function
Quick summary: The PHP strtotime() function parses an English textual datetime into a Unix timestamp.
PHP strtotime() Syntax
strtotime(string $datetime, ?int $baseTimestamp = null): int|falsePHP
PHP strtotime() Basic examples
var_dump(strtotime('2025-01-01'));PHP
Output:
int(1735689600)Parses a date string into a timestamp.
PHP strtotime() Real-world usage
$expires = strtotime('+1 day');
echo date('Y-m-d', $expires);PHP
Output:
2026-02-09Calculates expiration dates.
PHP strtotime() Edge cases
var_dump(strtotime('invalid date'));PHP
Output:
bool(false)Returns false for unparseable strings.
PHP strtotime() Common mistakes
Assuming strtotime always succeeds
Invalid input returns false.
Incorrect
strtotime($input);Correct
$ts = strtotime($input); if ($ts !== false) { /* use it */ }Always check the return value.
PHP strtotime() Frequently Asked Questions
What does strtotime() do?
Parses a date/time string into a Unix timestamp.
Why does strtotime() return false?
Invalid date format.
Use case?
Converting human-readable dates.
Supports relative formats?
Yes, like +1 day.
Timezone issues?
Depends on default timezone.
Common mistake?
Ambiguous formats.
Performance?
Fast.
Alternative?
DateTime objects.
Handles ISO dates?
Yes.
Returns timestamp?
Yes.
Safe?
Yes.
Best practice?
Use strict formats.