Dear grizzlygrowler
Yes, that will be my daughter's schedule too (but she will be doing it 5 days a week full time).
I don't know what to say - except that, when he comes home you can have your (limited) really precious time with him.... and weekends will be amazing. Very soon, too, he will be able to extend his time with you to (say) 8.00pm before he goes to bed. So long as he has good day time care he will always love you and know you are his mum. You have spent 6/7 months with him 24/7 - he loves you, knows you and will adapt to whatver comes next because you have been with him. Remember my lovely relative's saying: "your ways will be his ways".
Please, please, please don't beat yourself up... and DON'T LISTEN to any of the part-timers, SAHMs.... you are doing your best and he will always love you,
Also, I hesitate to say this...... make sure you keep him awake (and feeding)as much as you can during the day in the few weeks before you return to work... in my experience, that means he will sleep longer at night.
Apologies if you already know this - but if he's sleeping a good 6 hours during the day and, most importantly, having most of his food during the day he should be ready to sleep well at night! He needs at least 12/16hours sleep a day: make sure he gets most of them at night!!!!!!
Before I went back to work with my three (different schedules with each of them), I basically breast-fed them on demand from day one DURING THE DAY so they were really full when I put them down at 10.00pm-ish and then, from birth they all gradually cut out the 1.00am-ish feed,
So, they were sleeping basically from 10..00pm to 6.00am (one of mine managed this from 7.00pm to 6.00am at 7 weeks,,,, the other two took a lot longer!!). You will just need to make sure that the day care people keep him awake (and wake him to feed) during the day.
This worked for me 36/40 years ago with my three - so hope it might work for you!!!! Oh -and, by the way,the longest I managed to breast feed was 4 months.... it was not easy (and, certainly, in 1973 when I went back to work when my son was 5 months old there were no concessions with employers!!!!)
"BUT my main cause for concern is the grief of the loss of time with my little legs" Oh, how I understand this - my first day back at work (but it was only part-time) in November 1973 (he was five months old) is emblazoned on my heart for ever. But you have their whole amazing future ahead of you - enjoy it (and be prepared to be really p*ed off when he is 14 and unable to rouse himself from the pit before 2.00pm on Saturday!!)
Love you, hugs... just keep going - whatever you are doing is just fine! And good luck with your return to work.