THE CALENDAR is conspiring against the Democrats. They are bringing up social welfare legislation just as they are negotiating with the Republicans and the president over deficit control. A housing bill fell afoul of the contradiction earlier this week in the Senate. The welfare reform bill that was scheduled to come up in the House was wisely put off.

The Democratic bill is good legislation. The leadership should allow more latitude to amend it on the floor than the Rules Committee voted this week. But the basic structure ought to be approved -- and deserves to be considered outside the distorting context of the budget talks that have proceeded so sourly this week.

The bill would increase welfare spending, never a popular thing to do. But the legislation comes with its own financing mechanism, so that for the first three years (before all its provisions would be fully effective), it would pay its way. By the fifth year, when the bill would have taken full effect, the annual cost would be a little over $2 billion, of which the financing provisions would still pay about a third.

Much of the spending increase is intended to ease the passage of families off the rolls. States would be required, and given matching funds, to set up programs to pressure and help welfare mothers find jobs. The women themselves would also be given inducements. They would be allowed to stay on Medicaid longer than now, allowed to keep a slightly larger amount of earnings before their welfare checks went down and helped in the early months of work to pay day-care costs.

The rest of the money would go to extend welfare to families in which the father is at home but unemployed (half the states, including those with the largest welfare populations, already do this) and to sweeten the federal-state matching formula for states that agree to increase benefits. The House need hardly be embarrassed by doing this. Benefits, which the states control, have lost a third of their purchasing power to inflation in the past 15 years. A fifth of the children in the country now live below the federal poverty line.

Republicans criticize this Democratic package in part on grounds of cost, in part on the basis that, by raising benefits and through other provisions, it would reduce the incentive to work. But the Republicans offer little in return but a program of increasing pressure on beneficiaries to work, on pain of loss of benefits. That would reduce the rolls; it would not solve the problem. The Democrats have a more promising combination. The cost is modest. The worst it can do is slightly raise the incomes of a sector of the population in undoubted need.