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Mixed Date Formats

A single CSV where the date column uses 5 different formats — exactly what happens when a bank exports records that span a system migration or when someone manually edits an export.

Medium BANK
22
Total Rows
22
Valid (date+amount)
0
Invalid/Skipped
1
Warnings
A
Grade (100%)

Known Problems in This Document

  • MM/DD/YYYY and DD/MM/YYYY are ambiguous (is 03/04 March 4 or April 3?)
  • Some dates use "March 5, 2026" text format
  • One date is just "5-Mar" with no year
  • ISO format (2026-03-15) mixed with US format
  • European format with dots: 20.03.2026

Actual Parser Errors & Warnings

Warnings:
  • Could not parse date: N/A

Side-by-Side: Original Document vs Parser Extraction

Original Document Content (mixed_dates_bank.csv)
Parser Extraction Result
1 Date,Amount,Description,Reference,Balance
Skipped (header row)
2 03/01/2026,-4768.88,Payment to ACME Corp,TXN-10000,20231.12
2026-03-01 -4768.88 Payment to ACME Corp TXN-10000
3 02/03/2026,4833.62,Payment to Widget Co,TXN-10001,25064.74
2026-02-03 4833.62 Payment to Widget Co TXN-10001
4 2026-03-03,1470.54,Payment to Office Supply,TXN-10002,26535.28
2026-03-03 1470.54 Payment to Office Supply TXN-10002
5 "March 04, 2026",1121.08,Payment to CyberPay,TXN-10003,27656.36
2026-03-04 1121.08 Payment to CyberPay TXN-10003
6 05-Mar,739.86,Payment to FreshMart,TXN-10004,28396.22
2026-03-05 739.86 Payment to FreshMart TXN-10004
7 06.03.2026,3356.45,Payment to AutoParts Inc,TXN-10005,31752.67
2026-06-03 3356.45 Payment to AutoParts Inc TXN-10005
8 03-07-2026,4844.56,Payment to TechWorld,TXN-10006,36597.23
2026-03-07 4844.56 Payment to TechWorld TXN-10006
9 2026/03/08,-3926.32,Payment to QuickShip,TXN-10007,32670.91
2026-03-08 -3926.32 Payment to QuickShip TXN-10007
10 03/09/2026,4499.38,Payment to SafeGuard,TXN-10008,37170.29
2026-03-09 4499.38 Payment to SafeGuard TXN-10008
11 10/03/2026,-3838.33,Payment to MedSupply,TXN-10009,33331.96
2026-10-03 -3838.33 Payment to MedSupply TXN-10009
12 2026-03-11,-4299.16,Payment to CloudHost,TXN-10010,29032.80
2026-03-11 -4299.16 Payment to CloudHost TXN-10010
13 "March 12, 2026",-3658.56,Payment to PrintPro,TXN-10011,25374.24
2026-03-12 -3658.56 Payment to PrintPro TXN-10011
14 13-Mar,675.11,Payment to CleanStar,TXN-10012,26049.35
2026-03-13 675.11 Payment to CleanStar TXN-10012
15 14.03.2026,4589.47,Payment to FuelStop,TXN-10013,30638.82
2026-03-14 4589.47 Payment to FuelStop TXN-10013
16 03-15-2026,-1332.75,Payment to NetPay,TXN-10014,29306.07
2026-03-15 -1332.75 Payment to NetPay TXN-10014
17 2026/03/16,-2628.56,Payment to ACME Corp,TXN-10015,26677.51
2026-03-16 -2628.56 Payment to ACME Corp TXN-10015
18 03/17/2026,3078.1,Payment to Widget Co,TXN-10016,29755.61
2026-03-17 3078.10 Payment to Widget Co TXN-10016
19 18/03/2026,-3906.98,Payment to Office Supply,TXN-10017,25848.63
2026-03-18 -3906.98 Payment to Office Supply TXN-10017
20 2026-03-19,2294.19,Payment to CyberPay,TXN-10018,28142.82
2026-03-19 2294.19 Payment to CyberPay TXN-10018
21 "March 20, 2026",4394.73,Payment to FreshMart,TXN-10019,32537.55
2026-03-20 4394.73 Payment to FreshMart TXN-10019
22 04/03/2026,-250.00,AMBIGUOUS DATE - is this Apr 3 or Mar 4?,AMB-001,32287.55
2026-04-03 -250.00 AMBIGUOUS DATE - is this Apr 3 or Mar 4? AMB-001
23 06/05/2026,1200.00,ANOTHER AMBIGUOUS - Jun 5 or May 6?,AMB-002,33487.55
2026-06-05 1200.00 ANOTHER AMBIGUOUS - Jun 5 or May 6? AMB-002
24 ,-75.00,MISSING DATE ENTIRELY,NODATE-1,33412.55
Row not captured by parser
25 N/A,500.00,DATE IS N/A,NODATE-2,33912.55
Row not captured by parser
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