I was puzzled by this response, so I ran the test myself. Below are the results.

Based on this, I would re-word the manual a bit. I think the phrase "If the data file has no year number (f.i. MSFT.t6)" is misleading, since the first record in the t6 file (in November of 1999) is completely ignored.

Code
//#define INTRADAY
#define EXACTDATE

function run() {
#ifdef INTRADAY
	LogNumber = BarPeriod = 1;
#else
	LogNumber = BarPeriod = 1440;
#endif
#ifdef EXACTDATE
	LogNumber += 10000;
	StartDate = 20210712;
#else
	StartDate = 2021;
#endif

	set(LOGFILE);
	LookBack = 5;
	
	EndDate = 2022;
	assetList("AssetsIB");
#ifdef INTRADAY
	asset("EUR/USD"); // EURUSD_YYYY.t6, 2005 thru Feb 2022
#else
	asset("DIS"); // DIS.t6,  Nov 1999 thru Feb 2022
#endif
}

/*   ********* LOG OUTPUTS *********

BARPERIOD = 1440 (DAILY, YYYY)

V 2.464 on Sat 22-02-19 16:04:01 (Zorro S Subscription)
Test: test_startdate DIS 2021..2022
Assets AssetsIB

[1: Tue 21-01-05 15:40] (178.44)
[2: Wed 21-01-06 15:40] (179.12)
[3: Thu 21-01-07 15:40] (178.58)
[4: Fri 21-01-08 15:40] (178.69)
End of lookback period

[5: Mon 21-01-11 15:40] (179.09)
[6: Tue 21-01-12 15:40] (175.99)
[7: Wed 21-01-13 15:40] (176.12)
[8: Thu 21-01-14 15:40] (173.43)
...

BARPERIOD = 1440 (DAILY, YYYYMMDD)

V 2.464 on Sat 22-02-19 16:14:43 (Zorro S Subscription)
Test: test_startdate DIS 2021..2022
Assets AssetsIB

[1: Tue 21-07-06 15:40] (173.69)
[2: Wed 21-07-07 15:40] (172.82)
[3: Thu 21-07-08 15:40] (172.80)
[4: Fri 21-07-09 15:40] (177.04)
End of lookback period

[5: Mon 21-07-12 15:40] (184.38)
[6: Tue 21-07-13 15:40] (183.65)
[7: Wed 21-07-14 15:40] (183.42)
[8: Thu 21-07-15 15:40] (184.15)

BARPERIOD = 1 (INTRADAY, YYYY)

V 2.464 on Sat 22-02-19 16:04:01 (Zorro S Subscription)
Test: test_startdate EUR/USD 2021..2022
Assets AssetsIB

[1: Sun 21-01-03 23:01] (1.22375)
[2: Sun 21-01-03 23:02] (1.22344)
[3: Sun 21-01-03 23:03] (1.22358)
[4: Sun 21-01-03 23:04] (1.22364)
End of lookback period

[5: Sun 21-01-03 23:05] (1.22342)
[6: Sun 21-01-03 23:06] (1.22334)
[7: Sun 21-01-03 23:07] (1.22342)
[8: Sun 21-01-03 23:08] (1.22379)
...

BARPERIOD = 1 (INTRADAY, YYYYMMDD)

V 2.464 on Sat 22-02-19 16:13:30 (Zorro S Subscription)
Test: test_startdate EUR/USD 2021..2022
Assets AssetsIB

[1288: Sun 21-07-11 23:55] (1.18720)
[1289: Sun 21-07-11 23:56] (1.18726)
[1290: Sun 21-07-11 23:57] (1.18735)
[1291: Sun 21-07-11 23:58] (1.18734)
[1292: Sun 21-07-11 23:59] (1.18735)
End of lookback period

[1293: Mon 21-07-12 00:00] (1.18731)
[1294: Mon 21-07-12 00:01] (1.18731)
[1295: Mon 21-07-12 00:02] (1.18726)
[1296: Mon 21-07-12 00:03] (1.18734)
...

*/

www.vitaltrades.com - andrew@vitaltrades.com