Two hold times in the system, both in SYSTEM/TIMERS AND LIMITS. The HOLD timer is used for all stations by default, ALTERNATE HOLD is used for stations selected in SYSTEM/PHONE-RELATED INFO/FLAGS. Normally you'll set the regular timer to what most people need, then use alternate for those who need longer time like maybe file clerks who might have to dig for a while.
Also in TIMERS AND LIMITS is INTERDIGIT LONG and INTERDIGIT SHORT. Long is how long system will wait for another digit before you've dialed a valid number, short is used after 7 digits have been dialed. Note that if you increase short it will give you more time to dial, but if will also pause longer before analyzing the number and routing call, slowing down your call. All of this dialing info assumes you're using ARS...if you direct-select a trunk the carrier hears exactly what you dial as you dial it.