[TABLE="class: grid"]
<tbody>[TR]
[TD][/TD]
[TD]F
[/TD]
[TD]G
[/TD]
[TD]H
[/TD]
[TD]I
[/TD]
[/TR]
[TR]
[TD]1
[/TD]
[TD]cost code[/TD]
[TD]date[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]2
[/TD]
[TD]520
[/TD]
[TD]6/1/2017
[/TD]
[TD][/TD]
[TD]6/1/2017
[/TD]
[/TR]
[TR]
[TD]3
[/TD]
[TD]350
[/TD]
[TD]4/5/2017
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]4
[/TD]
[TD]520
[/TD]
[TD]8/7/2017
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]5
[/TD]
[TD]520
[/TD]
[TD]7/7/2017
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]
i2=MIN(IF(F2:F5=F2,G2:G5)) control +shift+enter format i2 as date
After you type in the formula, don't just press enter.
Instead, press CTRL + SHIFT + ENTER
If you've already entered the formula, then highlight the cell with the formula and press F2.
Then press CTRL + SHIFT + ENTER
When entered correctly, the formula will be enclosed in {brackets}