[rolf]

q)t:([]sym:`a`b`c`d`e;x:til 5)
q)t iasc`c`d?t`sym
sym x
-----
c 2
d 3
a 0
b 1
e 4

if you want to move the desired records to the top but want to preserve the order of the rest of the table

[rolf]

building on the above

rnd:{(`up`dn`nr!(f ceiling;(f:{string(x z*s)%s:10 xexp y})floor;.Q.f'))[z][;y;x]}

 

[rolf]

{key[x][i]!get[x]i:iasc key x:group(!). flip raze key[x],''get x}

indexing into the keys instead of doing a lookup a smidge faster

[rolf]

0: gets you the dashes in the date

[rolf]

i think this is what you are after

q)f:{abs(til[x]div 2)-x#(x-1),0} 

q)f each 2*1+til 5 

1 0 
3 0 2 1 
5 0 4 1 3 2 
7 0 6 1 5 2 4 3 
9 0 8 1 7 2 6 3 5 4

i cannot claim authorship

[rolf]

p is the 16th letter of the alphabet.  not likely a coincidence.

[rolf]

q)f:"T"0:2 1#"dt"$ 
q)f .z.p "2022-03-04T11:07:52.077" 

/ if you want to be picky about the type 
q)f:first"T"0:2 1#"dt"$ 
q)f .z.p "2022-03-04T11:08:49.988"