Filter table based on date

See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test (later on when you use the query on your dataset, you will have to change the source appropriately. If you have columns other than these, then delete Changed type step and do a Changed type for complete table from UI again)

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("ZY9BC4JAEIX/iuzZhTI6dDShICoiu4R4GHG0pXV3WZuD/fomTUSCOey8N9/smywTR/UmJUIRyQNpGUX8PFuRh+wAVWgK8jVrXHdse/2GNWgHDp5fbCNjqmdc7IMrFKqDx8D14ha1Zs6XOP+rN/dg2ILGkR+QMQGZF7Tcr+UJugEYU+w8quACpC2Ly8WUYhxIEUvrK1ZWf6cltoUGtOUjTFBikIB36rcoRTfN5h8=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Student Name" = _t, #"To submit as from" = _t, #"Submission optional (Yes/No)" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Student Name", type text}, {"To submit as from", type date}, {"Submission optional (Yes/No)", type text}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each [To submit as from]<=Date.StartOfWeek(Date.From(DateTime.FixedLocalNow()),1) or [To submit as from]=null),
    #"Filtered Rows" = Table.SelectRows(#"Added Custom", each ([Custom] = true)),
    #"Removed Columns" = Table.RemoveColumns(#"Filtered Rows",{"To submit as from", "Submission optional (Yes/No)", "Custom"})
in
    #"Removed Columns"