[exim] way to delay by time of day?

hmmm ... noone working on Sat nite =)

a question abt what i thought was going to be a simple task -- varying smtp
delay by time of day.

on a CGPro system, i run a cron job at various times of day to use its CLI to
change smmtp delay and # of available SMTP connections.

in exim, i'd like to make similar changes ...

the target, of course is:

    acl_check_connect:
        require  hosts   = *
        delay            = XXs

the best i can figure so far, one conceivable option is to assign delay to a
MACRO,

      delay = MY_DELAYs

and with a cron job, kill then relaunch EXIM with a "-DMY_DELAY=XXs" ( i don't
_think_ you can pass exim a -D param with just a sigHUP ...)

this seems a bit brute force/inelegant ...

another approach would be to reach OUT -- i.e., use a series of conditionals in
the 'delay =' stanza that use ${run<command> expansion to reach out to the
shell's date/time function ... but, again, 'kludgy'.

is there another/better approach for this?

thx!

richard