Automated system for checking and validating dates in Google Sheets

A complex formula has been developed based on ARRAYFORMULA, MAP, LAMBDA, LET, and LOOKUP, which automatically finds, analyzes, and verifies the correctness of dates between different tables without using scripts.

Key functions of the solution:
Mass processing of records through ARRAYFORMULA and MAP.
Automatic search for the last matching record in an external table by unique identifier.
Highlighting individual components of the date:
- day;
- month;
- year.
Converting the textual representation of the date into Google Sheets date format.
Checking the correctness of the date structure:
- presence of delimiters;
- correct length of the record;
- valid range of years;
- correspondence of day and month to the actual calendar date.
Automatic filtering out of incorrect or corrupted values.
Error handling through IFERROR, preventing failures when working with large data arrays.
Returning only valid dates for further use in business processes.
Technologies used:
- Google Sheets
- ARRAYFORMULA
- MAP
- LAMBDA
- LET
- LOOKUP
- IFERROR
- Working with dates and time values
- Logical data validation
Business result:
The created solution has allowed for the automation of data quality control in large tables, eliminating errors from manual date checks and ensuring the correctness of information before further processing or reporting.