|Summary Comparison of Female Reproductive System in Human and the Cynomolgus Monkey (Macaca fascicularis)||david h oconnor||2016-03-09|
How similar are macaque and human pregnancies? The attached file has a useful comparison (h/t Ted Golos). The source document can be found at: http://tpx.sagepub.com/content/36/7_suppl/171S.full.pdf+html and I believe it is available without a subscription.
In terms of timing, the average macaque pregnancy is about 160 days long.