dataset codification

Dear all, I am modeling some PK data from one rabbit. And I have some doubts how to codify the dataset. The rabbit received different single doses of a drug at different times. E.g, First of May it received a 100 mg dose i.v. , Then, 2 months latter (enough washout period), the first of July, it received and oral dose of 100mg. Finally, after other two months the rabbit received the last oral dose 200mg. I could codify in the TIME column the real times, including the jumps of two months, but I think that there is an option in Nonmem to “restart” the dose through the dataset. Could somebody clarify me this point? and perhaps include a simple example of dataset. Thank you in advance Mark