[NT6] Question about backfill with IB

[FireFly]

When doing a backfill of historical data, how is the time of the bars then determined?

What I mean is this:when I'm connected live, the timescale of my charts display the local time of my PC clock. But when I backfill, does it use my PC clock then or some timestamp that is connected with the data that is received from IB?

What happens for example when I change the local clock of my PC (for example if I travel to a different timezone). If I set my PC-clock for example a few hours back, will it then screw up the data in the database? If it uses the local clock as time reference then that would cause some data to overlap in the database. Or is there some kind of timestamp in the data received from the broker that will keep consistency of my database in that case?

Please explain. Thanks.

[NinjaTrader_Dierk]

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Backfill data will be timestamped with the time of your local PC clock. When you change the time of your PC clock, freshly loaded historical data might not be in sync with that you already have in your DB.

[FireFly]

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Thanks for clarifying this.

Since I have recently changed timezone of my PC-clock I better clear my database completely and rebuild it otherwise backtests could get messed up...
Is there an easy way to clear my database?

[NinjaTrader_Dierk]

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You may not need to reset your DB. You could reload all your data from your provider by Tools->Historical data->Reload.

[FireFly]

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But what if I cannot go far enough back for reloading the data? In that case the oldest data will be still the (wrong timeshifted) old data. Therefore I would prefer to clear the database completely before reloading.

[NinjaTrader_Dierk]

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I see. Sorry, then the only option is to delete the DB and start with a fresh one (which will be installed by NT on restart after you deleted the old one).

[FireFly]

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That's fine.
Which file(s) do I need to delete to start clear?

[NinjaTrader_Dierk]

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Please delete <my documents>/NinjaTrader6/db/NinjaTrader.mdb