I want to say about 2 years, but not "officially" the first year. We'll call my spouse "George", the ex "Jane" and the children "Judy" 5 and "Elroy" 10.
Jane was earning more than George when they separated. Just before the proceedings started she "left" her job and took a position earning 30k less. Knowing that Jane has a hard time keeping a job, we had her salary imputed. George agreed to pay full support at the outset of the process before realizing how long Jane would drag it out and because he was on the 40% bubble at the time. Jane wouldn't sign the final agreement unless George agreed to 1 year of full support, even though he was within 40/60.
We knew that this last year would be hard to make ends meet with paying the full support amount, but there was no other way to get an agreement done. This June was the light at the end of the tunnel.
(side note, I own/pay mortgage/bills on a separate home where I support my elderly mother. I contribute nothing to George's mortgage/bills.)
George provides an equal amount of parental care and financial support for the children when they're with him. Jane took all of the children's belongings when the household was divided leaving George to rebuild their home from scratch (clothing, toys, furniture, necessities, etc). Jane does not provide any items for the care of the children outside of their daily backpack/lunch bag.
We don't want to claim undue hardship, but without itemizing George vs Jane's lifestyle, our household’s standard of living is lower than Jane's standard of living. George has unusually high debts incurred to support the family before the separation (George took on all of the shared marital debt to remove it from the equation). Jane received a large payout on George's pension and a greater portion of the proceeds from the sale of their home as funds from her previous home had been used (and although not a factor per se, Jane's family is very wealthy). The amount of full support make it difficult to pay the required amount, let alone even conceive of planning for Judy/Elroy's future by starting an RESP.
We know that a reduction in CS to the offset should not affect the children in our situation and we can’t fathom what argument Jane could possibly have except plain greed.