DateTime Calculator
Add or subtract years, months, weeks, days, hours, minutes, and seconds to datetime inputs
DateTime
Calculator
Time
Converter
Batch
Time Values
DateTime Input
Supports ISO format, standard format, US format, date only, and Unix timestamps.
About This Tool
The DateTime Calculator allows you to add or subtract time values from datetime inputs. You can work with individual datetime values or process multiple values in batch.
Need to convert between seconds, minutes, hours, or other time units? Try our Time Converter tool for flexible time unit conversions.
If you have a list of Unix timestamps and want to convert them in bulk, check out the Batch Timestamp Converter for fast batch processing.
Explore more tools in our calculator tools collection.
Features:
- Add or subtract years, months, weeks, days, hours, minutes, seconds
- Support for multiple datetime formats
- Batch processing from text input or file upload
- Handles leap years and varying month lengths
- Download results as CSV file
- Copy results to clipboard
Supported Formats:
- ISO format: 2024-01-15T10:30:00Z
- Standard format: 2024-01-15 10:30:00
- US format: 1/15/2024 10:30 AM
- Date only: 2024-01-15
- Unix timestamps (seconds/milliseconds)
All processing happens in your browser - no data is sent to servers.
Frequently Asked Questions (FAQ)
What datetime formats are supported?
The tool supports ISO format (2024-01-15T10:30:00), standard format (2024-01-15 10:30:00), US format (1/15/2024 10:30), date only (2024-01-15), and Unix timestamps (both seconds and milliseconds).
Can I add and subtract different time units simultaneously?
Yes! You can combine years, months, weeks, days, hours, minutes, and seconds in a single operation. For example, add 1 year, 2 months, and 15 days all at once.
How does the tool handle leap years and month variations?
The calculator properly handles leap years and varying month lengths. When adding months or years, it accounts for the different number of days in each month and leap year considerations.
Is my data processed securely?
All processing happens in your browser. No datetime data is sent to any server, ensuring complete privacy and security of your information.
Can I process multiple datetime values at once?
Yes! You can enter multiple datetime values (one per line) in the text area or upload a file containing datetime values for batch processing. For advanced batch conversion of Unix timestamps, see our Batch Timestamp Converter.
What file formats can I upload?
You can upload TXT or CSV files containing datetime values. Each line should contain one datetime value in a supported format.
Examples
Sample Operations:
Add 1 year, 6 months:
2024-01-15 → 2025-07-15
2024-01-15 → 2025-07-15
Subtract 2 weeks, 3 days:
2024-06-15 → 2024-05-29
2024-06-15 → 2024-05-29
Add 5 hours, 30 minutes:
2024-01-15 10:00:00 → 2024-01-15 15:30:00
2024-01-15 10:00:00 → 2024-01-15 15:30:00
Sample Input:
2024-01-15 10:30:00 2024-03-20T14:45:30Z 1/15/2024 10:30 AM 2024-06-10 1642248600